Determination of a pseudo-binary SrSe–Ga 2Se 3 phase diagram and single crystal growth of SrGa 2Se 4 compounds

Abstract

We have investigated chemical reaction processes and thermal characteristics of IIa–III 2–VI 4 compounds in order to grow their single bulk crystals. Up to now, single crystals of Ca and Sr thiogallates have been successfully grown by the melt growth method based on their pseudo-binary phase diagrams. Here, a similar diagram of the SrSe–Ga 2Se 3 system has been constructed for the first time, where a eutectic reaction is found in the range of excess Ga 2Se 3 concentration, and it is shown that the SrGa 2Se 4 compound has a congruent melting point (1110 °C) suitable for the melt growth. A single crystal is grown from the melt by the horizontal Bridgman method. A trial is also made to grow a high-quality single crystal of CaGa 2S 4 already known as being grown easily.