PHASE-DIAGRAM EQUILIBRIA IN2SE3-SB2SE3 CRYSTAL-GROWTH OF THE BETA-IN2SE3 PHASE (IN1.94SB0.06SE3)

The phase diagram In2Se3-Sb2Se3 was constructed from DTA and X-ray dif fraction analysis data. No compound was observed in it, but two finite regions of In2Se3-based solid solutions were found: the first one, ca lled beta' (from 10 to 3.5 mol% Sb2Se3), of the tetradymite structure, and the second (from 3.5 to 0 mol% Sb2Se3) being the beta-In2Se3 stab ilized form. Crystals of the antimony-doped beta-In2Se3 form were grow n by the Bridgman method. This compound, the composition of which is I n1.94Sb0.06Se3, appears to be closely connected with the tetradymite s tructure. The refined unit-cell parameters of the hexagonal cell are a = 397(2) pm and c = 2827(2) pm. Its room temperature de conductivity is 2 x 10(-2) Omega cm(-1), and it is an n-type semiconductor with a b and gap of 1.34 eV. (C) 1998 Elsevier Science Ltd.