HIGH-PRESSURE SYNTHESIS OF USEFUL COMPLEX SULFIDES

采用原位X射线观察法和淬火法研究了硫、硫化铁（FeS）和锌硫属化物（ZnX; X = O，S，Se和Te）的高温高压行为。研究的压力和温度范围达16GPa和1000 ℃。测定了硫在12GPa以下高压条件下的熔化曲线，为高压条件下硫的合成提供了重要信息。与氧化物相比，还发现了硫化物的一些有趣的物理性质。在FeS的情况下，一个二级相变被发现，这可能是由铁原子的自旋有序解释。通过从头计算发现了一种新的具有B9（HgS）型结构的ZnSe高压相。根据硫的熔化曲线和硫化物的性质，在高温高压条件下合成了CaTiS_3、SrTiS_3和BaTiS_3等复合硫化物。

High-pressure and high-temperature behavior of sulfur, iron sulfide (FeS) and zinc chalcogenide (ZnX ; X=O, S, Se and Te) was investigated by in-situ X-ray observation method and quenching method. Pressure and temperature range for the investigation was up to 16GPa and 1000℃. The melting curve of sulfur under high-pressure condition up to 12GPa was determined, which was important information for synthesis of sulfides under high-pressure condition. Several interesting physical properties of sulfides were also found, compared with oxides. In the case of FeS, a second-order phase transition was found, which may be explained by a spin ordering of iron atoms. A new highpressure phase of ZnSe with the B9 (HgS)-type structure was found as predicted by an ab-initio calculation. On the basis of the melting curve of sulfur and the properties of sulfides, synthesis of several complex sulfides (CaTiS_3, SrTiS_3 and BaTiS_3) was tried under high-pressure and high-temperature conditions.