ZnGeP2多晶合成工艺改进及其X射线衍射分析

he stoichiometry of ZnGeP2 polycrystals synthesized by two-temperature vapor transport method deviates easily. Impurity phases of Ge and Zn3P2 and condensed layer of ZnP2 and P precipitates occurred in the inner wall of the synthesis crucible (quartz ampoule). We used a new synthesis process that combined mechanically oscillated furnace and vertical gradient cooling technique, modified synthesis equipment, and chose appropriate size of the quartz ampoule. We successfully synthesized the ZnGeP2 polycrystalline materials. Phase analysis was carried out using X-ray diffraction (XRD) on synthesized ZnGeP2 polycrystals. Whole pattern fitting refinement by Rietveld method was adopted, and then the relative contents of each phase were calculated by quantitative analysis. The results showed that synthesized ZnGeP2 using improved process is high-purity and single-phase, and that it can be used to grow ZnGeP2 crystals. We have grown integral ZnGeP2 crystal using the synthesized ZnGeP2 polycrystals as raw material. Its infrared transimittance in the range of 2.5~8.2 μm is close to 60% and it indicated that the optical quality of the grown crystal is good.