Accession Number : AD0274496

Title :   TEMPERATURE-PRESSURE PROJECTION OF THE THREE-PHASE LINE OF LEAD TELLURIDE

Corporate Author : NAVAL ORDNANCE LAB WHITE OAK MD

Personal Author(s) : BIS,RICHARD F.

Report Date : 01 JUL 1961

Pagination or Media Count : 38

Abstract : The temperature pressure projection of the threephase line was measured for PbTe using a double furnace arrangement. It was possible to obtain data only on the Te-rich limit of stability, as the partial pressure of PbTe is nearly equal to the partial pressure of diatomic Te at 910 C, and is always comparable to or greater than the partial pressure of Pb in equilibrium with the crystal of PbTe. R. F. Brebrick's theory, (J. Phys. Chem. Solids 18, 116, (1961)), for the limits of stability of a binary semiconductor MN was fitted between 400 and 600 C to the experimental data obtained, and to the results obtained elsewhere for the temperature-composition projection of the three-phase line. The theory contains three parameters: the Schottky constant, the intrinsic partial pressure, and the intrinsic carrier concentration, none of which were known. Assuming an intrinsic carrier concentration the other two parameters were calculated between 400 and 600 C and extrapolated to higher temperature. This was done for two estimates of the intrinsic carrier concentration. In both cases the Schottky constant and the intrinsic partial pressure and exponential functions of reciprocal temperature. The Te-rich limit of stability above 600 C was calculated using the parameters and the experimental data obtained. (Author)

Descriptors :   *INTERMETALLIC COMPOUNDS, *LEAD ALLOYS, *PHASE STUDIES, *SEMICONDUCTORS, *SINGLE CRYSTALS, *TELLURIUM ALLOYS, ALLOYS, CRYSTALS, TELLURIDES, TEMPERATURE, THEORY, THERMODYNAMICS, VAPOR PRESSURE

Distribution Statement : APPROVED FOR PUBLIC RELEASE