Acharya Nagarjuna University (ANU) 2005 M.Sc Information and Communication Technology SOLID STATE PHYSICS - 1 - Question Paper

M.Sc. (Final) DEGREE EXAMINATION,
DECEMBER 2005.
Second Year
Physics
Paper VII - SOLID STATE PHYSICS - 1

Time : 3 hours Maximum : 100 marks

ans any 5 ques..
All ques. carry equal marks.

1. What is co-ordination number? Determine the number of closest neighbours and the closest neighbour distance for monoatomic sc, bcc and fcc structures. Show that the atomic packing factors for fcc and hop metals are identical.

2. (a) Derive Bragg.s legal regulations for X-ray diffraction in crystals. define the principle of laue.s diffraction method and discuss the origin of Laue spots.

(b) define the powder methods for X-ray diffraction.

3. discuss with suitable examples the ionic covalent, metallic and molecular binding in solids.

4. Derive the dispersion relation for the frequency of lattice vibrations for linear monoatomic chain. explain the long wavelength limit.

5. define the Einstein model of lattice heat capacity. explain the successes and failures of this model.

6. (a) discuss in detail the free electron model in 3 dimensions.

(b) discuss the Fermi function and sketch Fermi distribution function for various temperatures.
7. define the basic principles of Hall effect in semiconductors. define an experimental set-up for the measurement of Hall voltage.

8. Show that the product of electron and hole concentrations in a semiconductor is constant at a provided temperature. How is the energy gap determined from the measurement of electrical conductivity of a semiconductor.

9. Write note on any 2 of the subsequent.

(a) Structure of diamond and co-ordinates of the atoms in the structure
(b) Experimental determination of elastic constants of solids.
(c) Motion of electrons in a periodic potential well
(d) Injection Laser.

Earning:   Approval pending.