Page 47 - CatalogNEP-PS

and Einstein, comparison with electronic heat capacity; Anharmonic effects in crystals - thermal
expansion.

UNIT 4 (5 Hours)
Dielectric properties of solids Electronic, ionic, and orientational polarization; static dielectric
constant of gases and solids; Complex dielectric constant and dielectric losses, relaxation time,
Debye equations; Cases of distribution of relaxation time, Cole - Cole distribution parameter,
Dielectric modulus; Ferroelectricity, displacive phase transition, Landau Theory of Phase
Transition.
UNIT 5 (8 Hours)

Magnetic properties of solids, Origin of magnetism; Diamagnetism: quantum theory of atomic
diamagnetism; Landau diamagnetism (qualitative discussion); Paramagnetism: classical and
quantum theory of paramagnetism; case of rareearth and iron-group ions; quenching of orbital
angular momentum; Van-Vleck paramagnetism and Pauli paramagnetism; Ferromagnetism:
Curie-Weiss law, temperature dependence of saturated magnetisation, Heisenberg‘s exchange
interaction, Ferromagnetic domains - calculation of wall thickness and energy; Ferrimagnetism
and antiferromagnetism.
Magnetic resonances:Nuclear magnetic resonances, paramagnetic resonance, Bloch equation,
longitudinal and transverse relaxation time; spin echo; motional narrowing in line width;
absorption and dispersion; Hyperfine field; Electron-spin resonance.

UNIT 6 (5 Hours)
Imperfections in solids: Frenkel and Schottky defects, defects by non stoichiometry; electrical
conductivity of ionic crystals; classifications of dislocations; role of dislocations in plastic
deformation and crystal growth; Colour centers and photoconductivity; Luminescence and
phosphors; Alloys, Hume-Rothery rules; electron compounds; Bragg - Williams theory, order-
disorder phenomena, superstructure lines; Extra specific heat in alloys.

UNIT 7 (7 Hours)
Superconductivity: Phenomenological description of superconductivity - occurrence of
superconductivity, destruction of superconductivity by magnetic field, Meissner effect; Type-I
and type-II superconductors; Heat capacity, energy gap and isotope effect; Outlines of the BCS
theory; Giaver tunnelling; Flux quantisation; a.c. and d.c. Josephson effect; Vortex state
(qualitative discussions); High Tc superconductors (information only).

PRACTICAL (30 Hours)

1. Measurement of lattice parameters and indexing of powder photographs.
2. Interpretation of transmission laue photographs.
3. Determination of orientation of a crystal by back reflection Laue method.
4. Rotation/oscillation photographs and their interpretation.
5. To study the modulus of rigidity and internal friction in metals as a function of
temperature.

7. To measure the cleavage step height of crystal by Multiple Fizeaue fringes.
8. To obtain Multiple beam Fringes of Equal Chromatic order.
6. To determine crystal step height and study birefringence.
7. To determine magnetoresistance of a Bismuth crystal as a function of magnetic field.
8. To study hysteresis in the electrical Polarization of a TGS crystal and measure the Curie
Temperature.

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