LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034
M.Sc. DEGREE EXAMINATION – PHYSICS
THIRD SEMESTER – NOVEMBER 2012
PH 3810 – SOLID STATE PHYSICS – I
Date : 01/11/2012 Dept. No. Max. : 100 Marks
Time : 9:00 – 12:00
PART – A
Answer ALL questions: (10×2=20)
- In a cubic unit cell, find the angle between normals to the planes (111) and (121)
- What is the difference between neutron diffraction and electron diffraction?
- Define density of phonon state.
- List the major contributions to the specific heat capacity.
- What do you understand by free electron gas.
- Write down the expression for the electronic contribution to specific heat capacity.
- Why a solid whose energy bands are filled cannot be a metal?
- Explain the concept of forbidden bands.
- Define Fermi surface.
- Explain electron and hole orbits.
PART – B
Answer any FOUR questions: (4×7.5=30)
- Derive Laue’s equations for diffraction of X-rays in a crystal lattice.
- Derive the w-k dispersion relationship for a one dimensional monoatomic lattice
- Write a note on Fermi-Dirac statistics and explain the effect of temperature on Fermi-Dirac statistics
- State and prove Bloch’s theorem.
- Discuss any one experimental method of Fermi surface study.
PART – C
Answer any FOUR questions : (4×12.5=50)
- Discuss in detail with diagram Laue and powder method of determining crystal structure
- Discuss the Debye model of lattice specific heat capacity. Explain how this model is able to account for low temperature and high temperature behaviour.
- Explain the concept of density of available electron states in three dimensions. Obtain the expressions for the Ef0 and average kinetic energy.
- Explain how the formation of bands in the Kronig-Penny model may be accounted for.
- Discuss the theory of effect of electric field on the Fermi surface.
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