X-RAY DETERMINATION OF THERMAL LATTICE EXPANSION OF CUSI2-TEMPERATURES(XP3 (X=1, 2) AT ELEVATED)

CuSi2P3 is a semiconductor having sphalerite structure with the space group F43mBAR with random distribution of the copper and silicon atoms on the cation sites. Silicon is soluble in CuSi2P3 upto 3 moles to fo rm CuSi2+xP3 (X = 1, 2, 3) compounds in single phase. In continuation of our work on thermal expansion of ternary semiconductors, CuSi3P3 cr ystals have been grown by a modified Bridgman method. Using a Unicam h igh temperature camera, the precision lattice parameter and the coeffi cient of thermal expansion (CTE) of CuSi3P3 at various high temperatur es have been evaluated from X-ray diffraction data. It has been found that the lattice parameter increases non-linearly while the coefficien t of thermal expansion increases linearly with temperature. The result s on thermal expansion of various semiconductors have been discussed i n terms of their ionicities.