1. D. Dalven, Infrared Phys. 9 (1969) 141.
2. A. K. Sharma and B. Singh, Indian J. Pure & Appl. Phys. 23 (1985) 135.
3. j. conragan and r. s. muller, The 1970 Solid State Sensors Symposium Conference Record, IEEE, Catalogue, No. 70C25-Sensor, P-52.
4. Prabhat Singh, Indian J. Pure & Appl. Phys. 18 (1980) 950.
5. m. a. angadi and v. thanigaimani, Thin Solid Films (Submitted).