Crystallography,seven crystal systems,Bravais space lattices,Braggs law.Powder diffraction method

1. MATRUSRI ENGINEERING COLLEGE
DEPARTMENT OF COMPUTER SCIENCE AND ENGINEERING
SUBJECT NAME: PHYSICS
FACULTY NAME: Dr. M. SREE LATHA

2. PHYSICS
COURSE OBJECTIVES: 1.To understand the knowledge of structures of different
solids and analysis of crystal structure by diffraction techniques.
2.To explain the behavior of matter particles using wave mechanics & basics of EM
theory.
3.To understand the knowledge of the band structure of solids and classification of
solids on the basis of band theory.
4.To understand the properties of semiconductors, superconductors, dielectric and
magnetic materials.
COURSE OUTCOMES: 1.Discuss fundamentals of crystal structures, structure
analysis techniques and crystal defects
2.Interpret concepts of band theory, semiconductors and polarizations of
dielectrics
3.Apply the knowledge of wave mechanics and electromagnetic theory in
engineering and technology
4.Explain magnetic materials and superconductors
5.Describe working of Lasers ,Optical fibers and their applications

3. PHYSICS SYLLABUS
Crystallography: Introduction – Types of crystal systems - Bravais lattices – Lattice planes
and Miller Indices (Cubic system) – Inter planar spacing (Cubic system) - Bragg’s law –
Powder diffraction method.
Crystal defects: Classification of point defects - Concentration of Schottky defects in
metals and ionic crystals - Concentration of Frankel defects – Line defects – Screw and Edge
dislocations – Burger’s vector.
UNIT- II
Band Theory of Solids & Semiconductors: Classical free electron theory (qualitative) –
Kronig-Penney model (qualitative treatment) - Energy band formation in solids - Intrinsic and
Extrinsic semiconductors - Concept of a hole - Carrier concentration and conductivity in
intrinsic semiconductors – Formation of P-N junction diode and its I-V characteristics –
Thermistor and its characteristics - Hall effect and its applications.
Dielectric Materials: Dielectrics - Types of polarizations – Electronic, Ionic, Orientational
and Space charge polarizations – Expression for Electronic polarizability - Frequency and
temperature dependence of dielectric polarizations - Determination of dielectric constant by
capacitance Bridge method - Ferro electricity - Barium titanate - Applications of
Ferroelectrics.

4. UNIT- III
WAVE MECHANICS: De-broglie concept of matter waves – De-broglie wavelength –
Physical significance and properties of wave function - Shcrödinger time dependent and
time independent wave equations - Particle in an infinite square well potential (particle in a
box).
ELECTROMAGNETIC THEORY: Review of steady and varying fields - Conduction
and displacement current - Maxwell’s equations in integral and differential forms.
Electromagnetic waves: plane wave equation – Poynting theorem.
UNIT- IV
MAGNETIC MATERIALS : Classification of magnetic materials dia, para, ferro,
antiferro and ferromagnetic materials-Weiss molecular field theory of ferromagnetism-
Magnetic domains –Hysteresis curve-Soft and hard magnetic materials-Poperties and
applications of ferrites.
SUPERCONDUCTIVITY: Introduction - general properties of super conductors -
Meissner effect - type i and type ii superconductors – BCS theory (qualitative) –
Introduction to high tc superconductors - Applications of superconductors.
PHYSICS SYLLABUS

5. UNIT- IV: Magnetic materials : Classification of magnetic materials dia, para, ferro,
antiferro and ferromagnetic materials-Weiss molecular field theory of ferromagnetism-
Magnetic domains –Hysteresis curve-Soft and Hard magnetic materials-properties and
applications of ferrites.
SUPERCONDUCTIVITY: Introduction - General properties of super conductors -
Meissner effect - Type I and type II superconductors – BCS theory (qualitative) – introduction
to high Tc superconductors - Applications of superconductors
UNIT-V: LASERS: Characteristics of lasers - Spontaneous and Stimulated emission of
radiation - Einstein’s coefficients - Population inversion - Ruby laser - Helium-Neon laser –
semiconductor laser – Applications of lasers.
FIBRE OPTICS: Introduction – Propagation of light through an optical fiber - Critical
angle - Aceptance angle - Numerical aperture (NA)– Types of optical fibers and Refractive
index pr
ofiles – Fibre drawing process (Double crucible method)- Application of optical fibers
TEXT BOOKS: 1.B.K.pandey and S.Chaturvedi, Engineering physics Cengage learning
2012
2.M.S. Avadhanulu and P.G. Kshirusagar, Engg. Physics, S. Chand & co. Ist edition
3.Snjay D jain & Girish G Sahasrabudhe- Engineering physics, university press.
PHYSICS SYLLABUS

6. REFERENCES: 1.R.K. Gaur and S. L. Gupta- Engineering physics, dhanpathrai
publications, New edition . 2.C.M. Srivastava and C. Srinivasan-Science of Engg
materials,New age international
COURSE PRE-REQUISITES: 1.Fundamentals of diffraction, crystalline and non
crystalline substances.
2.Atomic radius and co- ordination number and packing density
3. Fundamental theorems of probability.
4. Dual nature of light, wave groups or wave packets.
5. Basic laws of electromagnetism.
6.Concept of formation of energy bands (qualitative). fermi energy level
7.origin of magnetic field ,non-existence of magnetic monopoles.
8.Difference between ordinary rays and laser rays.
9.Fundamentals of light propagation through atmosphere and in medium. total
internal reflection
GAPS IN THE SYLLABUS : 1.Stirling’s formula for the calculation of defects in
crystals
2.Density of states for the calculation of carrier concentrations of semiconductors
PHYSICS PRE-REQUISITES & GAPS

7. MODULE-1:
CRYSTALLOGRAPHYAND CRYSTAL DEFECTS: Introduction, Types of
crystal systems, Crystalline solids Non-crystalline solids(Amorphous solids),Lattice
points and space lattice Basis, Crystal structure.
MODULE-2:
Unit cell and Lattice parameters, Crystal systems.
MODULE-3:
Bravais lattices. Lattice planes and Miller indices (Cubic system),Inter planar
spacing (Cubic system).
MODULE-4:
Expression for Lattice constant, Bragg’s Law.
MODULE-5:
X-Ray diffraction ,Crystal analysis-Powder diffraction method .
PHYSICS LECTURE PLAN UNIT-1

8. MODULE-6:
CRYSTAL DEFECTS: Introduction, Classification of crystal defects, types of
point defects, Impurity defects, vacancies.
MODULE-7:
Expression for concentration of Frenkel defects
MODULE-8:
Expression for concentration of Schottky defects in metals
MODULE-9:
Expression for concentration of Schottky defects in ionic crystal
MODULE-10:
Line defects, screw and edge dislocations, Burger`s vector.
PHYSICS LECTURE PLAN UNIT-1

9. INTRODUCTION:
The branch of science, which deals with the study of geometrical form and physical
properties of crystalline solids, is called crystallography.
Crystallography is the experimental science of determining the arrangement of
atoms in crystalline solids.
Crystals will have a regular periodic arrangement of atoms.
Any deviation from this periodicity is known as defects or imperfections in crystals.
The crystal defects affect their properties such as mechanical strength, ductility,
crystal growth, dielectric strength, magnetic hysteresis, conductivity, etc.
UNIT-I CRYSTALLOGRAPHY & CRYSTAL DEFECTS
OUTCOMES: Discuss fundamentals of crystal structures, structure analysis
techniques and crystal defects

10. CONTENTS:
1. INTRODUCTION
2. CRYSTALLINE SOLIDS NON-CRYSTALLINE SOLIDS(AMORPHOUS
SOLIDS)
3. LATTICE POINTS AND SPACE LATTICE BASIS
4. CRYSTAL STRUCTURE .
CRYSTALLOGRAPHY MODULE-1
OUTCOMES: By the end of this module student will be able to
1.Differentiate crystalline and amorphous solids.
2. Under stand space lattice and formation of crystal structure.

11. A solid composed of a closure collection of atoms. in solids, atoms are very
strongly held together. on the basis of arrangement of constituent particles
solids are divided into
1.Crystalline solids
2.Amorphous ( non crystalline solids)
Crystalline solids:
The crystalline state of solid is characterized
by regular and periodic arrangement of atoms
or molecules.
The crystalline solid may be further divided into
Single crystal (diamond, quartz, mica etc.)
Poly crystalline solids (metals, ceramics etc.)
CRYSTALLOGRAPHY MODULE-1

12. In single crystal, the periodicity
of atoms extends through out the
crystal (diamond, quartz)
A poly crystalline material is an aggregate
of number of small crystallites with
random orientations separated by well
defined boundaries. The smallest
crystallites are known as grains and the boundaries are grain boundaries.
CRYSTALLOGRAPHY MODULE-1
Amorphous Solids :
Amorphous solids are characterized by the complete
random arrangement of atoms or molecules.
The periodicity if at all present, extends up to
a distance of a few atomic diameters only.
In other words, these solids exhibit short range order

13. DIFFERENCE BETWEEN CRYSTALLINE AND AMORPHOUS SOLIDS
CRYSTALLOGRAPHY MODULE-1
S.No Crystalline Amorphous
1 The constituent particles
(atoms/molecules/ions)
are arranged in regular fashion
The constituent particles are not
arranged in any regular fashion
2 There is one repeating unit No repeating units
3 Have a long range order Have a short range order
4 They are anisotropic They are isotropic
5 They show elastic behavior They do not show elastic behavior
6 They are ductile in nature They are brittle in nature
7 They have sharp melting point i.e. all the
bonds are broken at particular temperature
as they are of equal strength
They melt over a range of
temperature as all bonds are of not
equal strength.

14. SPACE LATTICE : A space lattice may be defined as an infinite array of points in
three-dimensions in which every point has surroundings or environments identical
to that of every other point in the array.
It shows how atoms or molecules are arranged in a crystal
LATTICE POINTS: lattice points denote the position of atoms
or molecules in the crystals
The basis and Crystal structure
in order to obtain a crystal structure, an atom or group of atoms must be placed on
each lattice point in a regular fashion such an atom or group of atoms is called the
basis or the pattern.
when the basis is repeated with correct periodicity in all directions it gives the
actual crystal structure. the crystal structure is real, while the lattice is imaginary.
Mathematically it is expressed as
space lattice + basis -----------→ crystal structure
CRYSTALLOGRAPHY MODULE-1
Space Lattice + Basis = Crystal Structure
=
• • •
• • •
• • •

15. SUM UP:
1.Solids are broadly classified into two types
i) Crystalline solids ii) Amorphous solids
-Crystals are solids with regular structure of atoms or molecules.
-Amorphous solids that have no regular structure.
2. Space lattice is defined as an infinite array of lattice points in the space in which
every point has environment or surroundings identical to that of every other point
in the array.
3. Crystal structure = Lattice +Basis
CRYSTALLOGRAPHY MODULE-1

16. 1.Which of the following has a non crystalline structure? ( )
a) Iron b) Quartz c) Silica glass d) Tungsten
2.Every point of space lattice has……… ( )
a) Atoms b) Elements c) Lattice d) Identical
3.Lattice+basis = ( )
a) Unit cell b)Crystal c) Amorphous solid d) None
4. The amorphous substances possess ( )
a) Long range order b) short range order
c) ionic bonds only d) covalent bonds only
Crystallography Module-1
QUIZ

17. Questions
1. How are solids classified based on the internal structure?
2. Define space lattice ?
3. What is Basis?
CRYSTALLOGRAPHY MODULE-1

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