Basic characterization techniques of materials

1. Advance Material and Tool
Dr. Shailesh Mani Pandey
(Assistant Professor)
Department of Mechanical Engineering
National Institute of Technology Patna
Module - 2
Material Characterzation Techniques

2. Topics of the Lecture
Material Characterization Technique
 Scanning electron microscopy
 Transmission electron microscopy
 Atomic force microscopy
 Scanning tunneling microscopy
 Atomic absorption spectroscopy
 Differential scanning calorimetry

3. Committee on Characterization of Materials, Materials Advisory Board, National
Research Council developed the definition of Material Characterization: “ Characterization
describes those features of composition and structure (including defects) of a material that
are significant for a particular preparation, study of properties, or use, and suffice for
reproduction of the material ”.
 Materials Characterization has 2 main aspects:
- Accurately measuring the physical and chemical properties of materials
- Accurately measuring (determining) the structure of a material
(Atomic level structure & Microscopic level structures)
Mechanical, electrical and magnetic properties of a material are strongly dependent on
its structural characteristics. Therefore, material characterization is very important part of
any structure-property correlation exercise.

4.  Crystallography gives a concise representation of a large assemblage of species by
describing and characterizing the structure of crystals.
 It gives the ‘first view’towards understanding of the properties of the crystal.
CRYSTAL
A3D translationally periodic arrangement of atoms in a space is called a crystal.
LATTICE
A3D translationally periodic arrangement of points in a space is called a crystal.
Crystal = lattice + motif
MOTIF/BASIS
An atom or a group of atoms associated with each lattice point .
Lattice  the underlying periodicity of the crystal
Basis  Entity associated with each lattice points

5. UNIT CELL
SPACE LATTICE
A3D network of imaginary lines connecting the atoms.
 Smallest unit having the full symmetry of the crystal is called the unit cell.
 The simplest portion of a lattice that can be repeated by translation to cover the entire
1-D, 2-D, or 3-D space.
 The specific unit cell for each metal is defined by its parameters, which are the edges
of the unit cell a, b, c and the angles α (between b and c), β (between a and c) and γ
(between a and b).
 There are 14 possible types of space lattices (Bravais lattice), and they fall into 7
crystal systems.
a
b
c
α
β
γ
Replaces repeating element
( atoms, molecule, base etc.)

6. Crystal System Lattice Parameters Bravais Lattices
P I F C
1 Cubic (a = b = c,  =  =  = 90) 🗸 🗸 🗸
2 Tetragonal (a = b  c,  =  =  = 90) 🗸 🗸
3 Orthorhombic (a  b  c,  =  =  = 90) 🗸 🗸 🗸 🗸
4 Hexagonal (a = b  c,  =  = 90,  = 120) 🗸
5 Trigonal (a = b = c,  =  =   90) 🗸
6 Monoclinic (a  b  c,  =  = 90  ) 🗸 🗸
7 Triclinic (a  b  c,     ) 🗸
14 Bravais Lattices divided into 7 Crystal Systems
P Primitive
I Body Centred
F Face Centred
C A/B/C- Centred
ASymmetry based concept ‘Translation’based concept
‘symmetry’
Basis of definition
and
of crystals is
hence the
classification of crystals is also based
on symmetry

7. Microscope stand
 Carrier of all changeable
components
 High mechanical stability
 High thermal stability
 Precise focusdrive
illumination
condenser
stage
objective
tube lens
tube
eyepiece
Microscope Stand
Lampe house
 Integrated illumination for
transmitted light
 separate lampehouses for
incident- and transmitted light.
 special lampehouses for
fluorescence