RESEARCH ON II-VI COMPOUND SEMICONDUCTORS.
Quarterly rept. no. 2, 1 Apr-30 Jun 62,
CLEVITE CORP CLEVELAND OHIO ELECTRONIC RESEARCH DIV
Pagination or Media Count:
Efforts in the Second Quarter continue to emphasize phase equilibria in the system CdSe. The vapor pressure of CdSe determined by a free sublimation method in the temperature range 972 to 1247C yielded a standard heat and entropy of sublimation of 87 kcalmole and 53 cal moleK respectively. The temperature-pressure projection of the Se-rich portion of the CdSe phase diagram was approximately defined. New diffusion measurements at 1052 and 1100C give an activation energy for diffusion of Cd donors in CdSe of 88 kcalmole, and a pre-exponential term of 900,000 sq cm sec. Thermal expansion coefficients for ZnTe, CdSe, and CdSe were determined in the range 0 - 300C. A complete set of elastic, piezoelectric, and dielectric constants of ZnSe were obtained and are found to be intermediate in value between those of ZnS and ZnTe. The velocity of sound in CdSe and CdS calculated from elastic constants are found to be in good agreement with direct pulse-echo measurements. The critical field for sound amplification in CdS and CdSe for different modes of wave propagation are tabulated. Author
- Solid State Physics