The document discusses the atomic arrangements in crystalline solids. It defines key concepts such as crystals, lattice, basis, unit cell, coordination number, Miller indices, and common crystal structures including simple cubic, body centered cubic, and face centered cubic. It provides examples of calculating the number of atoms in a unit cell, lattice parameter, atomic packing factor, atomic concentration, and drawing and identifying crystallographic planes from their Miller indices.
1) The document explains Johann Balmer's empirical formula for the emission spectrum of hydrogen and how it relates the energies of emitted photons to integer values.
2) It then discusses early quantum models like the "electron in a box" model which showed energy must be quantized.
3) Finally, it describes Erwin Schrödinger's wave equation theory of quantum mechanics which successfully explained the quantization of energy levels in hydrogen and allowed prediction of atomic emission spectra.
The document summarizes key concepts related to crystal structure:
Crystalline materials have atoms or molecules arranged in a regular, orderly 3D pattern which gives them high strength, while non-crystalline materials have a random arrangement and lower strength. A crystal structure is a regular repetition of this 3D pattern defined by a unit cell and space lattice. Common crystal structures include simple cubic, body-centered cubic, face-centered cubic, and hexagonal close-packed. Crystal defects such as point defects, dislocations, grain boundaries, and voids are also discussed.
This document discusses crystal field stabilization energy (CFSE), which is the energy gap between split d-orbital energy levels caused by ligands interacting with a central metal atom. It provides information on how CFSE is calculated for octahedral and tetrahedral complexes, and factors that affect CFSE such as the nature of ligands and metal cation, complex geometry, and the metal's quantum number.
The document provides information about crystal structures, including:
1) It discusses space lattices, which are arrangements of points that repeat periodically in 3D space, with every point having an identical surrounding. The smallest repeating unit of a lattice is called the primitive cell.
2) There are 14 possible crystal structures defined by unique combinations of lattice parameters (a, b, c values and α, β, γ angles). The structures differ in packing efficiency and symmetry.
3) Miller indices are used to specify crystallographic directions and planes, helping to understand properties that vary by orientation like strength and conductivity. Understanding planes and directions is important for predicting deformation and failure modes in materials.
There are three main types of crystalline solids: ionic solids, molecular solids, and metallic solids. Ionic solids are composed of positive and negative ions arranged in a crystal lattice. They have properties like high melting points and are brittle. Molecular solids have molecules arranged in a particular configuration, and properties like low melting points and being nonconductors. Metallic solids have metal atoms or ions arranged in patterns, giving properties such as conductivity and malleability. All crystalline solids have constituents ordered in highly organized, repeating microscopic structures extending in three dimensions.
This document summarizes different types of crystal systems and lattice structures, including cubic, orthorhombic, rhombohedral, tetragonal, triclinic, and hexagonal systems. It also describes common Bravais lattices like primitive, FCC, and BCC. Finally, it discusses packing of layers in cubic close packing and hexagonal close packing, and defines octahedral and tetrahedral voids that can exist in FCC and hexagonal unit cells.
The document discusses periodicity and how properties vary across periods and down groups in the periodic table. It specifically focuses on Period 3 elements (Na to Ar). Key points:
1) Atomic radius decreases across Period 3 as nuclear charge increases, attracting electrons more strongly. Radius increases down groups as atomic size increases.
2) Ionization energy generally increases across Period 3 as nuclear charge increases, requiring more energy to remove electrons. It decreases down groups as distance from nucleus increases.
3) Melting/boiling points are highest for metals/covalent networks and lower for weak molecular bonds. Electrical conductivity is highest for metals and lowest for nonmetals.
1) The document explains Johann Balmer's empirical formula for the emission spectrum of hydrogen and how it relates the energies of emitted photons to integer values.
2) It then discusses early quantum models like the "electron in a box" model which showed energy must be quantized.
3) Finally, it describes Erwin Schrödinger's wave equation theory of quantum mechanics which successfully explained the quantization of energy levels in hydrogen and allowed prediction of atomic emission spectra.
The document summarizes key concepts related to crystal structure:
Crystalline materials have atoms or molecules arranged in a regular, orderly 3D pattern which gives them high strength, while non-crystalline materials have a random arrangement and lower strength. A crystal structure is a regular repetition of this 3D pattern defined by a unit cell and space lattice. Common crystal structures include simple cubic, body-centered cubic, face-centered cubic, and hexagonal close-packed. Crystal defects such as point defects, dislocations, grain boundaries, and voids are also discussed.
This document discusses crystal field stabilization energy (CFSE), which is the energy gap between split d-orbital energy levels caused by ligands interacting with a central metal atom. It provides information on how CFSE is calculated for octahedral and tetrahedral complexes, and factors that affect CFSE such as the nature of ligands and metal cation, complex geometry, and the metal's quantum number.
The document provides information about crystal structures, including:
1) It discusses space lattices, which are arrangements of points that repeat periodically in 3D space, with every point having an identical surrounding. The smallest repeating unit of a lattice is called the primitive cell.
2) There are 14 possible crystal structures defined by unique combinations of lattice parameters (a, b, c values and α, β, γ angles). The structures differ in packing efficiency and symmetry.
3) Miller indices are used to specify crystallographic directions and planes, helping to understand properties that vary by orientation like strength and conductivity. Understanding planes and directions is important for predicting deformation and failure modes in materials.
There are three main types of crystalline solids: ionic solids, molecular solids, and metallic solids. Ionic solids are composed of positive and negative ions arranged in a crystal lattice. They have properties like high melting points and are brittle. Molecular solids have molecules arranged in a particular configuration, and properties like low melting points and being nonconductors. Metallic solids have metal atoms or ions arranged in patterns, giving properties such as conductivity and malleability. All crystalline solids have constituents ordered in highly organized, repeating microscopic structures extending in three dimensions.
This document summarizes different types of crystal systems and lattice structures, including cubic, orthorhombic, rhombohedral, tetragonal, triclinic, and hexagonal systems. It also describes common Bravais lattices like primitive, FCC, and BCC. Finally, it discusses packing of layers in cubic close packing and hexagonal close packing, and defines octahedral and tetrahedral voids that can exist in FCC and hexagonal unit cells.
The document discusses periodicity and how properties vary across periods and down groups in the periodic table. It specifically focuses on Period 3 elements (Na to Ar). Key points:
1) Atomic radius decreases across Period 3 as nuclear charge increases, attracting electrons more strongly. Radius increases down groups as atomic size increases.
2) Ionization energy generally increases across Period 3 as nuclear charge increases, requiring more energy to remove electrons. It decreases down groups as distance from nucleus increases.
3) Melting/boiling points are highest for metals/covalent networks and lower for weak molecular bonds. Electrical conductivity is highest for metals and lowest for nonmetals.
Contains information about various crystal types in solid state chemistry like Rock Salt, Wurtzite, Nickel Arsenide, Zinc Blende etc. It also gives a brief description of lattice energy and Born Haber cycle.
CBSE Class 12 Chemistry Chapter 1 (The Solid State) | Homi InstituteHomi Institute
The document discusses various types of bonding and intermolecular forces found in solid state materials, including covalent bonding, metallic bonding, ionic bonding, hydrogen bonding, and van der Waals forces. It also describes different types of crystal defects such as point defects, line defects, stoichiometric defects, impurity defects, and non-stoichiometric defects. Finally, it covers topics like semiconductors, ferromagnetism, and the magnetic properties associated with orbiting and spinning electrons.
The document discusses electronegativity, which is defined as the attractive force between an atom's nucleus and its valence electrons. It describes Allred and Rochow's definition of electronegativity as being directly proportional to the effective nuclear charge and inversely proportional to the square of the covalent radius. It also lists the factors that affect an element's effective nuclear charge, including the size of the atom, total nuclear charge, screening by inner electrons, and penetration of outer electrons into the nucleus. Finally, it shows the relationship between effective nuclear charge, electronegativity, and molybdenum's common oxidation states.
IB Chemistry on Polarity, Hydrogen Bonding and Van Der Waals forcesLawrence kok
This document provides a tutorial on chemical bonding including ionic bonds, covalent bonds, polarity, hydrogen bonding, and intermolecular forces. It discusses how ionic bonds form through the transfer of electrons between metals and nonmetals, and how covalent bonds form through the sharing of electrons between nonmetals. It also explains how polarity arises from unequal sharing of electrons and differences in electronegativity. Additional concepts covered include London dispersion forces, dipole-dipole interactions, factors that influence boiling points, and the properties of hydrogen bonding.
INTRODUCTION:
Hybrid Orbitals
Developed by Linus Pauling, the concept of hybrid orbitals was a theory created to explain the structures of molecules in space. The theory consists of combining atomic orbitals (ex: s,p,d,f) into new hybrid orbitals (ex: sp, sp2, sp3).
Crystals are solids with atoms arranged in regular repeating patterns in all directions. There are several key concepts in crystallography:
1) Crystals have a crystal lattice structure defined by lattice vectors and a unit cell that repeats to form the crystal.
2) Unit cells have lattice constants and contain one or more atoms. Primitive, body-centered, and face-centered unit cells have different atomic packing factors.
3) Crystal structures demonstrate symmetry operations like translation and rotation that leave the structure unchanged. Miller indices represent crystallographic planes and directions.
Crystals are composed of repeating unit cells that generate the entire crystal structure when translated through space. A crystal's symmetry is defined by symmetry elements like rotations, translations, and reflections that leave the crystal unchanged. There are 32 possible point groups and 14 Bravais lattices that combine to form 230 unique space groups describing all possible crystal symmetries. The asymmetric unit is the smallest portion of the unit cell that generates the full crystal structure through symmetry operations.
The document describes the lever rule, which is used to determine both the compositions of phases present at a given temperature in a multi-phase alloy system, as well as the relative amounts of each phase. It explains that a tie line is drawn through the given composition point on a phase diagram. The intercepts of the tie line with phase boundaries indicate the compositions of the phases. The relative amounts of each phase are inversely proportional to the distances from the composition point to the intercepts with each phase boundary.
IB Chemistry on Absorption Spectrum and Line Emission/Absorption SpectrumLawrence kok
Transition metal complexes can have different colors due to the splitting of the metal ion's d orbitals caused by ligands. Ligands of varying strength cause varying degrees of d orbital splitting, represented by ΔE. Stronger ligands cause greater splitting and absorption of higher energy visible light, resulting in colors like violet or blue. Weaker ligands cause less splitting and absorption of lower energy visible light, appearing as colors like yellow or green. The spectrochemical series orders ligands from weakest to strongest field strength based on the color produced.
A reaction intermediate or an intermediate is a molecular entity that is formed from the reactants (or preceding intermediates) and reacts further to give the directly observed products of a chemical reaction.
This document provides information about the characteristics of d-block elements, also known as transition elements. It discusses their electronic configuration, variable valence, magnetic properties, catalytic properties, and ability to form complexes. It describes the first, second, and third transition series and provides examples of common oxidation states for elements in each series. The document also discusses the importance of d-block elements in applications such as metals, magnets, batteries, paints and more. It provides tables of typical oxidation states for different transition element groups.
Non-Stoichiometry & Solid Solution
The document discusses various types of point defects that can occur in non-stoichiometric compounds including Schottky defects, Frenkel defects, and anti-site defects. It provides examples of intrinsic point defects in metal-deficient, metal-excess, oxygen-deficient, and oxygen-excess metal oxides. Solid solutions are formed when one or more minor components dissolve uniformly within the crystal lattice of a major component. Types of solid solutions include interstitial, substitutional, ordered, and disordered solutions. Experimental techniques like X-ray diffraction and density measurements can be used to study properties of non-stoichiometric compounds and solid solutions.
Corrosion And Its Prevention (Electrochemical Interpretation) Awais Chaudhary
This document discusses corrosion and its prevention through an electrochemical interpretation. It begins by defining corrosion as the deterioration of materials through chemical interaction with the environment, and notes that while it affects many materials, the discussion will focus on iron and steel corrosion. It then provides examples of corrosion, explains why metals corrode in terms of thermodynamics, and outlines the general scheme of corrosion when a metal is immersed in an aqueous solution. The document continues by explaining the electrochemistry of corrosion, including the components of a corrosion cell, current flow, and the mechanism of rusting. It classifies types of corrosion such as uniform, galvanic, crevice, pitting and intergranular corrosion. Finally, it discusses some
This document discusses the differences between amorphous and crystalline solids. Amorphous solids lack a definite shape or order of atomic arrangement, while crystalline solids have a defined shape and long-range order. Crystalline solids are anisotropic, meaning their properties vary with direction, because their atomic structure is ordered, whereas amorphous solids are isotropic with uniform properties in all directions due to their irregular atomic arrangement. The document then covers topics such as unit cell types, crystal axes and angles, calculating packing factors, defects in crystalline structures, and line defects.
Metal carbonylates are complexes containing carbonyl ligands bonded to a metal in a negative oxidation state, such as Re(CO)-5 and Mn(CO)-5. They are prepared by treating a metal carbonyl like Fe(CO)5 or Re2(CO)10 with sodium amalgam. Metal carbonylates are used in organic synthesis to catalyze reactions like reductive methylation of aldehydes and ketones or saturation of α,β unsaturated carbonyl compounds. Their bonding involves donation of electron density from the metal's orbitals to the carbonyl ligands' antibonding orbitals to fill the metal's valence shell according to the 18 electron rule.
This document provides an overview of key concepts in chemical kinetics, including:
1) Factors that affect reaction rates such as concentration, temperature, and catalysts.
2) Methods for determining reaction rates by measuring changes in concentration over time.
3) How reaction rates depend on concentration according to rate laws and rate constants.
This document discusses coordination chemistry and methods for detecting complex formation in solutions. It defines coordination chemistry as the study of compounds with a central metal atom surrounded by ligands. Various methods are described for detecting when a complex forms in solution, including changes in solubility, color, conductivity, absorption spectra, pH, and chemical properties. The document also discusses Lewis acid-base concepts in coordination chemistry and defines stability constants and factors that influence stability.
The Born-Lande equation describes the lattice energy (U) of an ionic crystal as a function of the charges on the cation (Z+) and anion (Z-), the equilibrium interionic distance (r0), and other physical constants. It includes contributions from the Madelung constant, Coulomb interactions, and short-range repulsion. The document provides an example application of the Born-Lande equation to calculate the lattice energies of various ionic crystals such as LiF, CsI, and MgO.
Crystallography is the experimental science of determining the arrangement of atoms in crystalline solids. Crystallography is a fundamental subject in the fields of materials science and solid-state physics (condensed matter physics). The word crystallography is derived from the Ancient Greek word κρύσταλλος (krústallos; "clear ice, rock-crystal"), with its meaning extending to all solids with some degree of transparency, and γράφειν (gráphein; "to write"). In July 2012, the United Nations recognised the importance of the science of crystallography by proclaiming that 2014 would be the International Year of Crystallography.
Solid state physics by Dr. kamal Devlal.pdfUMAIRALI629912
This document provides an overview of the course "Solid State Physics" (PHY503). The course covers topics like crystal structure, types of lattices, crystal symmetry, and important crystal structures such as sodium chloride, diamond, and hexagonal close packed. It defines key terms used to describe crystal structure like lattice, basis, unit cell, primitive cell, and Miller indices. It also summarizes different crystal systems and lattice types as well as structural properties of common crystalline materials.
Contains information about various crystal types in solid state chemistry like Rock Salt, Wurtzite, Nickel Arsenide, Zinc Blende etc. It also gives a brief description of lattice energy and Born Haber cycle.
CBSE Class 12 Chemistry Chapter 1 (The Solid State) | Homi InstituteHomi Institute
The document discusses various types of bonding and intermolecular forces found in solid state materials, including covalent bonding, metallic bonding, ionic bonding, hydrogen bonding, and van der Waals forces. It also describes different types of crystal defects such as point defects, line defects, stoichiometric defects, impurity defects, and non-stoichiometric defects. Finally, it covers topics like semiconductors, ferromagnetism, and the magnetic properties associated with orbiting and spinning electrons.
The document discusses electronegativity, which is defined as the attractive force between an atom's nucleus and its valence electrons. It describes Allred and Rochow's definition of electronegativity as being directly proportional to the effective nuclear charge and inversely proportional to the square of the covalent radius. It also lists the factors that affect an element's effective nuclear charge, including the size of the atom, total nuclear charge, screening by inner electrons, and penetration of outer electrons into the nucleus. Finally, it shows the relationship between effective nuclear charge, electronegativity, and molybdenum's common oxidation states.
IB Chemistry on Polarity, Hydrogen Bonding and Van Der Waals forcesLawrence kok
This document provides a tutorial on chemical bonding including ionic bonds, covalent bonds, polarity, hydrogen bonding, and intermolecular forces. It discusses how ionic bonds form through the transfer of electrons between metals and nonmetals, and how covalent bonds form through the sharing of electrons between nonmetals. It also explains how polarity arises from unequal sharing of electrons and differences in electronegativity. Additional concepts covered include London dispersion forces, dipole-dipole interactions, factors that influence boiling points, and the properties of hydrogen bonding.
INTRODUCTION:
Hybrid Orbitals
Developed by Linus Pauling, the concept of hybrid orbitals was a theory created to explain the structures of molecules in space. The theory consists of combining atomic orbitals (ex: s,p,d,f) into new hybrid orbitals (ex: sp, sp2, sp3).
Crystals are solids with atoms arranged in regular repeating patterns in all directions. There are several key concepts in crystallography:
1) Crystals have a crystal lattice structure defined by lattice vectors and a unit cell that repeats to form the crystal.
2) Unit cells have lattice constants and contain one or more atoms. Primitive, body-centered, and face-centered unit cells have different atomic packing factors.
3) Crystal structures demonstrate symmetry operations like translation and rotation that leave the structure unchanged. Miller indices represent crystallographic planes and directions.
Crystals are composed of repeating unit cells that generate the entire crystal structure when translated through space. A crystal's symmetry is defined by symmetry elements like rotations, translations, and reflections that leave the crystal unchanged. There are 32 possible point groups and 14 Bravais lattices that combine to form 230 unique space groups describing all possible crystal symmetries. The asymmetric unit is the smallest portion of the unit cell that generates the full crystal structure through symmetry operations.
The document describes the lever rule, which is used to determine both the compositions of phases present at a given temperature in a multi-phase alloy system, as well as the relative amounts of each phase. It explains that a tie line is drawn through the given composition point on a phase diagram. The intercepts of the tie line with phase boundaries indicate the compositions of the phases. The relative amounts of each phase are inversely proportional to the distances from the composition point to the intercepts with each phase boundary.
IB Chemistry on Absorption Spectrum and Line Emission/Absorption SpectrumLawrence kok
Transition metal complexes can have different colors due to the splitting of the metal ion's d orbitals caused by ligands. Ligands of varying strength cause varying degrees of d orbital splitting, represented by ΔE. Stronger ligands cause greater splitting and absorption of higher energy visible light, resulting in colors like violet or blue. Weaker ligands cause less splitting and absorption of lower energy visible light, appearing as colors like yellow or green. The spectrochemical series orders ligands from weakest to strongest field strength based on the color produced.
A reaction intermediate or an intermediate is a molecular entity that is formed from the reactants (or preceding intermediates) and reacts further to give the directly observed products of a chemical reaction.
This document provides information about the characteristics of d-block elements, also known as transition elements. It discusses their electronic configuration, variable valence, magnetic properties, catalytic properties, and ability to form complexes. It describes the first, second, and third transition series and provides examples of common oxidation states for elements in each series. The document also discusses the importance of d-block elements in applications such as metals, magnets, batteries, paints and more. It provides tables of typical oxidation states for different transition element groups.
Non-Stoichiometry & Solid Solution
The document discusses various types of point defects that can occur in non-stoichiometric compounds including Schottky defects, Frenkel defects, and anti-site defects. It provides examples of intrinsic point defects in metal-deficient, metal-excess, oxygen-deficient, and oxygen-excess metal oxides. Solid solutions are formed when one or more minor components dissolve uniformly within the crystal lattice of a major component. Types of solid solutions include interstitial, substitutional, ordered, and disordered solutions. Experimental techniques like X-ray diffraction and density measurements can be used to study properties of non-stoichiometric compounds and solid solutions.
Corrosion And Its Prevention (Electrochemical Interpretation) Awais Chaudhary
This document discusses corrosion and its prevention through an electrochemical interpretation. It begins by defining corrosion as the deterioration of materials through chemical interaction with the environment, and notes that while it affects many materials, the discussion will focus on iron and steel corrosion. It then provides examples of corrosion, explains why metals corrode in terms of thermodynamics, and outlines the general scheme of corrosion when a metal is immersed in an aqueous solution. The document continues by explaining the electrochemistry of corrosion, including the components of a corrosion cell, current flow, and the mechanism of rusting. It classifies types of corrosion such as uniform, galvanic, crevice, pitting and intergranular corrosion. Finally, it discusses some
This document discusses the differences between amorphous and crystalline solids. Amorphous solids lack a definite shape or order of atomic arrangement, while crystalline solids have a defined shape and long-range order. Crystalline solids are anisotropic, meaning their properties vary with direction, because their atomic structure is ordered, whereas amorphous solids are isotropic with uniform properties in all directions due to their irregular atomic arrangement. The document then covers topics such as unit cell types, crystal axes and angles, calculating packing factors, defects in crystalline structures, and line defects.
Metal carbonylates are complexes containing carbonyl ligands bonded to a metal in a negative oxidation state, such as Re(CO)-5 and Mn(CO)-5. They are prepared by treating a metal carbonyl like Fe(CO)5 or Re2(CO)10 with sodium amalgam. Metal carbonylates are used in organic synthesis to catalyze reactions like reductive methylation of aldehydes and ketones or saturation of α,β unsaturated carbonyl compounds. Their bonding involves donation of electron density from the metal's orbitals to the carbonyl ligands' antibonding orbitals to fill the metal's valence shell according to the 18 electron rule.
This document provides an overview of key concepts in chemical kinetics, including:
1) Factors that affect reaction rates such as concentration, temperature, and catalysts.
2) Methods for determining reaction rates by measuring changes in concentration over time.
3) How reaction rates depend on concentration according to rate laws and rate constants.
This document discusses coordination chemistry and methods for detecting complex formation in solutions. It defines coordination chemistry as the study of compounds with a central metal atom surrounded by ligands. Various methods are described for detecting when a complex forms in solution, including changes in solubility, color, conductivity, absorption spectra, pH, and chemical properties. The document also discusses Lewis acid-base concepts in coordination chemistry and defines stability constants and factors that influence stability.
The Born-Lande equation describes the lattice energy (U) of an ionic crystal as a function of the charges on the cation (Z+) and anion (Z-), the equilibrium interionic distance (r0), and other physical constants. It includes contributions from the Madelung constant, Coulomb interactions, and short-range repulsion. The document provides an example application of the Born-Lande equation to calculate the lattice energies of various ionic crystals such as LiF, CsI, and MgO.
Crystallography is the experimental science of determining the arrangement of atoms in crystalline solids. Crystallography is a fundamental subject in the fields of materials science and solid-state physics (condensed matter physics). The word crystallography is derived from the Ancient Greek word κρύσταλλος (krústallos; "clear ice, rock-crystal"), with its meaning extending to all solids with some degree of transparency, and γράφειν (gráphein; "to write"). In July 2012, the United Nations recognised the importance of the science of crystallography by proclaiming that 2014 would be the International Year of Crystallography.
Solid state physics by Dr. kamal Devlal.pdfUMAIRALI629912
This document provides an overview of the course "Solid State Physics" (PHY503). The course covers topics like crystal structure, types of lattices, crystal symmetry, and important crystal structures such as sodium chloride, diamond, and hexagonal close packed. It defines key terms used to describe crystal structure like lattice, basis, unit cell, primitive cell, and Miller indices. It also summarizes different crystal systems and lattice types as well as structural properties of common crystalline materials.
Dear aspirants,
This presentation includes basic terms of crystallography, a brief note on unit cell and its type With derivation of its properties: APF, Coordination no., No. of atoms per unit cell and also its atomic radius. I also added 7 Crystal System, Bravais Lattice and finally Miller Indices concept.
Hope this presentation is helpful.
Any questions or clarifications are welcomed.
This document provides an overview of crystallography and crystal structures. It discusses how crystals form periodic arrangements that can be described by unit cells defined by lattice parameters. The most common crystal structures for metals are face-centered cubic (FCC), body-centered cubic (BCC), and hexagonal close-packed (HCP) since metals form dense, ordered packings with low energies. These crystal structures differ in their unit cell contents and atomic packing factors (FCC has the highest at 0.74). Directions in crystals are described by Miller indices written as [uvw].
The study of crystal geometry helps to understand the behaviour of solids and their
mechanical,
electrical,
magnetic
optical and
Metallurgical properties
Crystal physics deals with the study of crystalline solids and their physical properties. Single crystals are needed because they exhibit uniform physical properties and directional properties. There are two main types of solids - crystalline and amorphous. Crystalline solids such as metals have a regular arrangement of atoms while amorphous solids like glass have an irregular arrangement. Crystalline solids can be single crystalline or polycrystalline. Important crystallographic concepts include the unit cell, lattice points, Miller indices, and Bravais lattices which describe the geometric arrangement of atoms in crystals. Common crystal structures are simple cubic, body centered cubic, face centered cubic, and hexagonal close packed.
- The document discusses different crystal structures including simple cubic, body-centered cubic, face-centered cubic, and hexagonal closely packed.
- Key properties like number of atoms per unit cell, atomic radius, coordination number, and atomic packing factor are defined and calculated for each structure.
- There are seven basic crystal systems that materials can belong to depending on their lattice parameters and angles between axes. The most common systems are cubic, hexagonal, and tetragonal.
This document discusses the atomic arrangement and properties of crystalline solids such as metals. It begins by describing the long-range order in crystalline solids compared to the short-range order in amorphous solids. It then discusses various crystal structures including cubic, hexagonal, and body-centered cubic. It provides examples of calculating properties like atomic packing factor and theoretical density based on crystal structure. Finally, it discusses using X-ray diffraction to determine crystal structure by measuring spacing between crystal planes.
This document discusses crystal structures and lattice planes. It begins by defining a crystal as having atoms or molecules arranged in a periodic three-dimensional pattern. The smallest repeating unit of a crystal structure is called the unit cell, which is defined by its axial lengths and interaxial angles. There are 14 possible lattice arrangements known as Bravais lattices. Miller indices are used to describe lattice planes, which are determined by taking the reciprocals of the intercepts of a plane with the crystal axes and multiplying by the least common denominator. Bragg's law of diffraction is mentioned as the reason X-rays are useful for crystallography due to their wavelengths being on the order of atomic distances.
This document provides an overview of crystallography. It defines key terms like crystalline solids, unit cell, space lattice, and basis. Crystalline solids have long-range order of atoms while amorphous solids do not. There are 7 crystal systems based on lattice parameters. Miller indices (hkl) are used to describe planes in a crystal lattice. Bragg's law relates the wavelength of X-rays to the diffraction pattern produced by the crystal structure. Common defects in crystal structures are discussed like vacancies, interstitials, and Frenkel and Schottky defects. Methods for determining crystal structures include X-ray crystallography and powder diffraction.
This document discusses crystal structures, including periodic arrays of atoms, fundamental lattice types, crystal planes indexed using Miller indices, and imaging atomic structures. It covers common lattice types like simple cubic, body-centered cubic, and face-centered cubic. Simple crystal structures presented include sodium chloride, cesium chloride, diamond, and zinc sulfide. Non-ideal crystal structures can involve random stacking or polytypism with long repeat units along stacking axes.
This document discusses crystal structures, including periodic arrays of atoms, fundamental lattice types, crystal planes indexed using Miller indices, and imaging atomic structures. It covers common lattice types like simple cubic, body-centered cubic, and face-centered cubic. Simple crystal structures presented include sodium chloride, cesium chloride, diamond, and zinc sulfide. Non-ideal crystal structures can involve random stacking or polytypism with long repeat units along stacking axes.
This document provides an overview of solid state structures. It discusses the two main types of solids - crystalline and amorphous - and explains their distinguishing characteristics. Crystalline solids have a definite, orderly arrangement of atoms while amorphous solids do not. The document then covers various topics related to crystalline solids, including crystal structures, unit cells, Bravais lattices, and the structures of materials like NaCl, diamond, and graphite. It also discusses crystal imperfections and different types of defects that can occur in ionic crystals.
Space lattice, Unit cell, Bravais lattices (3-D), Miller indices, Lattice planes, Hexagonal closed packing (hcp) structure, Characteristics of an hcp cell, Imperfections in crystal: Point defects (Concentration of Frenkel and Schottky defects).
X – ray diffraction : Bragg’s law and Bragg’s spectrometer, Powder method, Rotating crystal method.
The document discusses different types of solids and crystal structures. It begins by stating that everything around us is matter, which is made of molecules and exists in four main types. It then discusses crystalline and amorphous solids, and the key differences between them. Crystalline solids like metals can have either a single crystal or polycrystalline structure. The document also covers various crystal structures like simple cubic, body centered cubic, face centered cubic, and diamond cubic. It defines important concepts such as unit cell, lattice points, Miller indices, coordination number and packing factor.
Crystal and Crystal Systems PowerPoint PresentationMuhammadUsman1795
1. Crystals are composed of atoms arranged in regular repeating patterns in three dimensions. The basic repeating unit is called the unit cell, which is defined by its lattice parameters of a, b, c, and the angles between them.
2. There are seven possible crystal systems depending on the geometry of the unit cell. Common crystal structures include body-centered cubic, face-centered cubic, and hexagonal close-packed.
3. Crystal structures are described using Miller indices to specify points, directions, and planes within the unit cell. Key crystallographic concepts include families of planes and directions.
The document discusses crystal structure and defects. It begins by classifying materials as amorphous, polycrystalline, or crystalline based on their atomic structure. Crystalline materials have an orderly array of atoms described by a lattice and basis. Common crystal structures include simple cubic, body centered cubic, and face centered cubic. Defects in the crystal structure are also discussed, including point defects like vacancies and interstitials, and line defects like dislocations. Miller indices are used to describe planes and directions in crystal structures.
Temple of Asclepius in Thrace. Excavation resultsKrassimira Luka
The temple and the sanctuary around were dedicated to Asklepios Zmidrenus. This name has been known since 1875 when an inscription dedicated to him was discovered in Rome. The inscription is dated in 227 AD and was left by soldiers originating from the city of Philippopolis (modern Plovdiv).
Gender and Mental Health - Counselling and Family Therapy Applications and In...PsychoTech Services
A proprietary approach developed by bringing together the best of learning theories from Psychology, design principles from the world of visualization, and pedagogical methods from over a decade of training experience, that enables you to: Learn better, faster!
Beyond Degrees - Empowering the Workforce in the Context of Skills-First.pptxEduSkills OECD
Iván Bornacelly, Policy Analyst at the OECD Centre for Skills, OECD, presents at the webinar 'Tackling job market gaps with a skills-first approach' on 12 June 2024
it describes the bony anatomy including the femoral head , acetabulum, labrum . also discusses the capsule , ligaments . muscle that act on the hip joint and the range of motion are outlined. factors affecting hip joint stability and weight transmission through the joint are summarized.
How to Make a Field Mandatory in Odoo 17Celine George
In Odoo, making a field required can be done through both Python code and XML views. When you set the required attribute to True in Python code, it makes the field required across all views where it's used. Conversely, when you set the required attribute in XML views, it makes the field required only in the context of that particular view.
Walmart Business+ and Spark Good for Nonprofits.pdfTechSoup
"Learn about all the ways Walmart supports nonprofit organizations.
You will hear from Liz Willett, the Head of Nonprofits, and hear about what Walmart is doing to help nonprofits, including Walmart Business and Spark Good. Walmart Business+ is a new offer for nonprofits that offers discounts and also streamlines nonprofits order and expense tracking, saving time and money.
The webinar may also give some examples on how nonprofits can best leverage Walmart Business+.
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Walmart Business + (https://business.walmart.com/plus) is a new shopping experience for nonprofits, schools, and local business customers that connects an exclusive online shopping experience to stores. Benefits include free delivery and shipping, a 'Spend Analytics” feature, special discounts, deals and tax-exempt shopping.
Special TechSoup offer for a free 180 days membership, and up to $150 in discounts on eligible orders.
Spark Good (walmart.com/sparkgood) is a charitable platform that enables nonprofits to receive donations directly from customers and associates.
Answers about how you can do more with Walmart!"
2. Crystal: Definition
⚫A crystalline solid is a solid in which the
atoms bond with each other in a regular
pattern to form a periodic array of
atoms.
⚫Crystals are constructed by the infinite
repetition of identical structural units in
space.
⚫The most important property of a crystal is
periodicity, which leads to what is termed
long-range order.
3. Lattice and Basis
⚫All crystals can be described in terms of a
lattice and a basis.
⚫A lattice is an infinite periodic array of
geometric points in space, without any
atoms.
⚫When we place an identical group of
atoms or molecules, called a basis, at
each lattice point, we obtain the actual
crystal structure.
4. Lattice and Basis
⚫ The crystal is thus a lattice plus a basis at each lattice point.
⚫ Crystal = Lattice + Basis
⚫ Crystals with the same lattice but different basis create
different crystalline solids but have the same symmetry.
⚫ Here, we have a simple square 2D lattice, and the basis has 2
atoms.
5. Unit Cell
⚫ The unit cell is the most convenient building block unit in
the crystal structure that carries the properties of the
crystal. The repetition of the unit cell in three
dimensions generates the whole crystal structure.
⚫ In the previous example, the unit cell is a simple square
with two atoms.
6. Unit Cell
⚫ Crystals are made up of 3-dimensional arrays of
atoms. Since unit cell is the smallest repeating
unit having the full symmetry of a crystal
structure, crystal structure is described in terms
of the geometry of arrangement of particles in the
unit cell.
⚫ Unit cells can be visualized in the 2 following ways:
◦ Hard sphere representation: Atoms are denoted by
hard, touching spheres showing their realistic
arrangement.
◦ Reduced sphere representation: For clarity, it is
often more convenient to draw the unit cell with the
spheres reduced in size and the distance between
spheres highly exaggerated.
8. Simple Cubic
⚫ The unit cell is cubic with one atom at each of the eight
corners.
⚫ Because atoms are shared with neighboring cells, only one-
eighth of the corner atoms belong to each unit cell. So the
number of atoms per unit cell is: 8 corners x 1/8 = 1
⚫ Rare due to low packing density (0.52), only Polonium (Po)
has this structure.
Close packed hard sphere unit cell Reduced sphere unit cell
9. BCC Crystals
⚫ The unit cell is cubic with one atom at each of the eight corners
and one atom at the center of the cell.
⚫ Because atoms are shared with neighboring cells, only once-
eighth of the corner atoms belong to each unit cell. So there are
effectively 2 atoms in the space of the unit cell (1 center + 8
corners x 1/8).
Close packed hard sphere unit cell Reduced sphere unit cell
Note: In a
true BCC
cell all
atoms are
identical,
the center
atom is
shaded
differently
only for
ease of
viewing.
10. BCC Crystals
⚫The body centered atom is in contact with all
the eight corner atoms. Each corner atom is
shared by eight unit cells and hence, each of
these atoms is in touch with eight body
centered atoms.
⚫Atoms touch each other along cube
diagonals.
⚫Examples: iron, chromium, tungsten, niobium,
vanadium, barium.
⚫Volume of the BCC unit cell is 68 percent
full of atoms, which is high but lower than the
maximum possible packing.
11. Generation of BCC structure
through unit cell repetition
Note: In the simulation some space is allowed between the atoms for better visibility, but
originally the atoms in a BCC structures touch each other along cube diagonals.
12. FCC Crystals
⚫ The unit cell is cubic with one atom at each of the eight corners
and one atom at the center of each of the six faces.
⚫ Because atoms are shared with neighboring cells, only one-eighth
of the corner atoms and half of the face centered atom belong to
each unit cell. There are effectively 4 atoms in space of the unit
cell (6 face x 1/2 + 8 corners x 1/8).
Close packed hard sphere unit cell Reduced sphere unit cell
13. FCC Crystals
⚫Atoms touch each other along face
diagonals.
⚫Examples: copper, nickel, gold, and silver.
⚫Volume of the FCC unit cell is 74
percent full of atoms, which is the
maximum possible packing possible
with identical spheres.
⚫Also known as Close Packed Cubic
(CPC) structure.
14. Generation of FCC structure
through unit cell repetition
Note: In the simulation some space is allowed between the atoms for better visibility, but
originally the atoms in a FCC structures touch each other along face diagonals.
15. ⮚ The number of nearest neighbours of which an
atom has in the unit cell of any crystal
structure.
Examples
⮚ Simple Cubic (SC) coordination number = 6
⮚ Body-Centered Cubic(BCC) coordination number = 8
⮚ Face-Centered Cubic(FCC) coordination number = 12
Coordination Number
24. Atomic Packing Factor
⚫Atomic packing factor (APF) or packing
efficiency indicates how closely atoms are
packed in a unit cell and is given by the
ratio of volume of atoms in the unit cell
and volume of the unit cell.
28. Unit cell geometry
⚫ To establish a reference frame
and to apply three-dimensional
geometry, we insert an xyz
coordinate system. The x, y, and
z axes follow the edges of the
parallelepiped and the origin is at
the lower-left rear corner of the
cell.
⚫ The unit cell extends along the x
axis from 0 to a, along y from 0
to b, and along z from 0 to c.
⚫ Conventionally the geometry of the unit cell is represented as
a parallelepiped with sides a, b, and c and angles α, β, and γ,
as depicted in figure. The sides a, b, and c and angles α, β, and
γ are referred to as lattice parameters.
29. Miller lndices
⚫ Miller indices of a plane refers to the general
convention for describing a particular plane in
a crystal based on three-dimensional geometry.
⚫ They are the reciprocals of the (three) axial
intercepts for a plane, cleared of fractions & common
multiples.
⚫ Algorithm
1) Choose a origin and unit cell of convenience (the plane
should not pass through the origin, if it does, shift the
origin or draw a plane parallel to it by an appropriate
translation).
2) Read off intercepts of plane with axes in terms of a, b, c
3) Take reciprocals of intercepts
4) Clear all fractions without reducing to smallest integer
values
5) Enclose in parentheses, no commas i.e., (hkl)
30. Miller lndices Example
⚫ Intercepts of the plane are a/2, b, and ∞ along x, y, z axis (the plane
is parallel to the z axis) respectively, so intercepts in terms of a, b,
c are ½, 1, and ∞.
⚫ Taking reciprocals of intercepts we get 1/(½) , 1/1, 1/ ∞ = 2,1,0.
⚫ This set of numbers does not have fractions, so it is not necessary
to clear fractions.
⚫ Hence, the Miller indices (hkl) are (210).
31. Miller lndices
⚫ If there is a negative integer due to a negative intercept, a
bar is placed across the top of the integer.
⚫ Also, if parallel planes differ only by a shift that involves a
multiple number of lattice parameters, then these planes may
be assigned the same Miller Indices. indices. For example, the
plane (010) is the xz plane that cuts the y axis at —b. If we
shift the plane along y by two lattice parameters (2b), it will
cut the y axis at b and the Miller indices will become (010).
¯
32. Miller lndices
⚫ Planes can have the same Miller indices only if they are
separated by an integer multiple of the lattice
parameter. For example, the (010) plane is not identical to
the (020) plane, even though they are geometrically parallel.
The (020) plane cannot be shifted by the lattice parameter b
to coincide with plane (010).
(010) (020)
33. Drawing Planes from Miller Indices
◦ Draw unit cell
◦ Shift origin if necessary. Must if the plane passes through origin,
advisable if negative integers present in Miller Indices. (Example: If
negative integer is along z axis, move origin along the positive
direction of z axis.)
◦ Invert the given indices to get intercepts
◦ Plot the intercepts along the x, y, z axis for non-∞ values.
34. Drawing Planes from Miller Indices
◦ For a single ∞ value, plot the
other 2 values and connect.
Then draw 2 lines along the
axis with the ∞ value, starting
from the intercept points and
ending at the unit cell surface.
Connect the points where
these lines end at the surface.
Example: (110), (101)
¯
35. Drawing Planes from Miller Indices
◦ For two ∞ values, plot the single non-∞
value and draw 2 lines along the axes
with the ∞ value, starting from the
intercept point and ending at the unit
cell surface. Draw another 2 lines the
same way, but starting from the points
where the previous lines ended.
Example: (100),(100)
¯
36. Example 1.13
⚫ Consider the FCC unit cell of the copper crystal
shown in the figure.
a. How many atoms are there per unit cell?
b. If R is the radius of the Cu atom, show that the
lattice parameter a is given by a = R 2√ 2
c. Calculate the APF.
d. Calculate the atomic concentration (number of
atoms per unit volume) and the density of the
Crystal given that the atomic mass of copper is
63.55 gmol-1 and the radius of the Cu atom is
0.128nm.
37. Example 1.13
a)
There are four atoms per
unit cell. The Cu atom at
each corner is shared with
eight other adjoining unit
cells. Each Cu atom at the
face center is shared with
the neighboring unit cell.
Thus, the number of atoms in the unit cell
= 8 corners (1/8 atom) + 6 faces (1/2 atom)
= 4 atoms.
38. b)
Consider one of the cubic
faces in above figure.
The face is a square of side a
and the diagonal
is or .
The diagonal has one atom at
the center of diameter 2R,
which touches two atoms at
the corners.
Example 1.13
The diagonal, going from corner to corner, is therefore R + 2R +R
= 4R.
⇒ 4R =
⇒
40. d) In general, atomic concentration is:
where x= number of atoms in unit cell.
From part (a), we know that x =4 for Cu.
Since 1 mole of matter weighs Mat grams and contains NA atoms,
each atom weighs Mat/NA grams.
Example 1.13
41. Example 1.14
a. Find the Miller Indices for the plane shown in
the figure which passes through one side of a
face and the center of an opposite face in the
Cu FCC lattice with a=0.3620 nm.
b. Draw (100) and (110) crystallographic planes
for the lattice.
c. Calculate the planar concentration for each of
these planes.
42. Example 1.14
Since the plane passes through the origin at the lower-left
rear corner, we place the origin to point 0’ at the lower-right
rear corner of the unit cell.
In terms of lattice parameter a:
x, y, and z axes intercepts: ∞, -1, 1/2
reciprocals: 0, -1, 2
Miller indices: (012) ¯
43. Example 1.14
⚫To calculate the planar concentration
n(hkl) on a given (hkl) plane, we consider a
bound area A of the plane within the unit
cell and treat it as the repeat unit in 2D.
Only atoms whose centers lie on A are
involved in the calculation.
⚫For each atom, we then evaluate what
portion of the atomic cross section (a
circle in 2D) cut by the plane (hkl) is
contained within A.
44. Example 1.14
The (100) plane corresponds to a cube face
and has an area A = a2. There is one full
atom at the center; that is, the (100) plane
cuts through one full atom, one full circle in
two dimensions, at the face center.
However, not all corner atoms are within A.
Only a quarter of a circle is within the bound
area.
45. Example 1.14
⚫ Number of atoms in A = (4 corners) x 1/4
atom) + 1 atom at face center = 2
⚫ Planar concentration n(100) of (100) is:
46. Example 1.14
⚫ Consider the (110) plane. The number of atoms in
the area A = (a)(a √ 2) defined by two face diagonals
and two cube sides is:
⚫ (4 corners) x 1/4 atom) + (2 face diagonals) x (1/2
atom at diagonal center) = 2
⚫ Planar concentration n(110) of (110) is: