Differential thermal analysis and crystal growth of AgGaS2

AgGaS2 has been studied using differential thermal analysis (DTA) technique. The melting point and solidification temperature of AgGaS2 were determined, indicating its large supercooling degree. A phase transformation point has been found. It was concluded by discussions with the DTA results and the phase diagram that the excess Ga2S3 came inevitably out of the AgGaS2 as precipitates of an intermediate phase (named Ag2Ga20S31). The results optimized the growth parameters and heat treatment procedures. Large, high optical quality AgGaS2 crystals have been obtained, and after heat treatment, it can be used for optical devices.