The phase diagram for the binary system indium-tellurium and electrical properties of In3Te5

Abstract

The phase diagram for the binary system indium-tellurium has been clarified and corrected, particularly in the region near the composition In2Te3. This material is a potentially important semiconductor, either alone or in combination with other materials, such as Cu3Te, Ag2Te, CdTe, etc.Results of this study were obtained by correlating differential thermal analysis (DTA), chemical analyses of zone-refined ingots, microscopic analysis, and X-ray determinations.Two new phases have been identified, and the compositions of three other phases have been determined more precisely. (1) The phase In2Te (33.3 at. %Te) does not exist; the composition should be In9Te7 (43 at. %Te). The peritectic decomposition temperature is 462[deg]C. (2) The phase InTe (50.0 at. % Te) has the composition In30Te31 (50.8 at. % Te). The congruent melting point is 696[deg]C. (3) A new phase In3Te4 (57.0 at. % Te) has been found having a peritectic decomposition temperature of 650[deg]C. (4) The phase In2Te3 (60.0 at. % Te) has the composition In27Te40 (59.7 at.% Te). The congruent melting point is 667[deg]C, and there is a phase transition at about 550[deg]C. (5) A new phase In3Te5 (62.5 at. % Te) has been found, having a peritectic decomposition temperature of 625[deg]C, and a phase transition at 463[deg]C. (6) The phase In2Te5 (71.5 at. % Te) was prepared. (7) Electrical measurements on In3Te5 show a large conductivity increase associated with the phase transition at 463[deg]C. (8) Electrical measurements on zone refined In2Te3, were non-reproducible.