Bharathiar University 2007 M.Phil Crystal Physics -e - Question Paper

M.Phil. Crystal Physics May-June 2007

Time : 3 hours Maximum : 100 marks
ans any 5 ques..
All ques. carry equal marks.
(5 * 20 = 100)
1. What are primary nucleation and secondary nucleation? explain the formation of edge dislocation and screw dislocation during the crystal growth process. discuss with necessary diagrams.
2. Define solubility. discuss the method of measurement of supersaturation and explain with Meir's solubility diagram.
3. Explain the mechanism of gel formation in silica gel media and explain the method of crystal growth using U-tube. List the merits and demerits of gel growth.
4. What is meant by zone refining? define the method of zone refining process and discuss how purification is achieved?
5. Describe the crystal growth process using crystal pulling technique. elaborate the requirements and restrictions in this method?
6. Explain the principles of flux growth technique. explain about option of flux with an example. List the merits and demerits in flux growth.
7. Discuss the mechanism of chemical vapour deposition. define a method of growing single crystals by chemical vapour deposition technique. What is the uniqueness in this method?
8. Write notes on the subsequent :
(a) Critical size in nucleation
(b) Molecular beam method.

Earning:   Approval pending.