Techniques of Materials Characterization

Por: Swayam . en: ,

Week 1:
  1. Introduction to microscopy

  1. Basic principles of image formation

  2. General concepts of microscopy: resolution. Magnification, depth of field, depth of focus etc.

  1. Optical microscopy

  1. Image formation, contrast development

  2. Basic components (light sources, specimen stage, lens system, optical train etc.)

Week 2:
  1. Various modes of optical microscopy

  1. Bright field mode (transmission vs. reflection)

  2. Contrast enhancing modes (dark field, polarized light, interference contrast, fluorescent microscopy etc.)

Week 3:
  1. General concepts of electron microscopy

  1. Basic components of electron microscope (electron gun, electro-magnetic lenses etc.)

  2. Aberrations (chromatic, spherical, astigmatism etc.) and their corrections

  3. Electron-materials interaction (elastic vs. inelastic scattering, coherent vs. incoherent scattering, interaction volume)

Week 4:
  1. Transmission electron microscopy (TEM)

  1. Image formation and contrast generation (mass-thickness contrast, atomic number contrast, diffraction contrast etc.)

  2. Modes of TEM (bright field, dark field, HAADF, STEM)

  1. Electron diffraction in TEM

  1. Scattering of electrons in crystalline material (Braggs law, zone axis, order of diffraction etc.)

Week 5:
  1. Electron diffraction in TEM

  1. Concept of reciprocal lattice, Ewald sphere, diffraction from finite crystal

  2. Diffraction pattern (Single crystal vs. polycrystalline diffraction, selected area diffraction etc.),

  3. Indexing of diffraction pattern (camera constant, structure

  4. Application of electron diffraction (DF imaging, dislocation contrast, phase identification etc.)

Week 6:
  1. Scanning electron microscopy (SEM)

  1. Working principle in scanning mode

  2. Signal generation: Inelastic scattering (Secondary vs. backscattered electron, Auger electrons, characteristic X-ray emission etc.)

Week 7:
  1. Basic components of SEM

  1. Detectors: SE (E-T detector), BSE (scintillator vs. solid state), in-lense detector

  2. Optics of SEM (magnification, pixel, resolution, depth of field)

  3. Resolution in SEM (minimum probe size, beam current etc.)

Week 8:
  1. Chemical analysis in SEM

  1. EDS and WDS detectors

  1. Imaging and contrast generation in SEM

  1. Topographic imaging (in SE & BSE mode)

  2. Compositional imaging (BSE mode)

Week 9:
  1. X-ray production

  1. Electromagnetic radiation, continuous spectrum, characteristic spectrum

  1. X-ray absorption (adsorption edge, excitation voltage, Auger effect etc.), X-ray filters

Week 10:
  1. ntensities of diffracted beams

  1. Scattering by single electron (Thomson and Crompton scattering)

  2. Scattering by single atom: atomic scattering factor

Week 11:
  1. Intensities of diffracted beams

  1. Scattering from unit cell: structure factor calculation for various crystal systems

  2. Multiplicity factor and temperature factor

Week 12:
  1. X-ray diffraction profile and analysis

  1. FWHM and line broadening

  2. Crystallite size effect and Scherrer formula

  3. Effect of strain (tensile vs compressive, uniform vs. non-uniform)

  4. Amorphous vs. crystalline materials