Pb_2MoO_5单晶的坩埚下降法生长

Growth of Pb_2MoO_5 Single Crystal by Bridgman Method

本文报道了Pb2MoO5单晶的坩埚下降法生长工艺。按照精确的化学计量比进行配料，应用高温固相反应合成Pb2MoO5多晶料；在晶体生长过程中，控制炉体温度于1050～1070℃，调节固液界面温度梯度为30～40℃／cm，按照0．6～1．0mm／h的下降速率，通过改进的坩埚下降法生长出透明完整的Pb2M005单晶；应用X射线衍射、差热分析、透射光谱等方法进行了单晶基本性质的表征。X射线衍射分析证实该晶体为单斜晶系，DTMTC,曲线表明该晶体在958℃一致熔融，高于此温度熔体组分出现严重挥发，该晶体在可见光波长范围具有良好的光学透过性，其吸收边位于370nm波长附近。

The growth of Pb2MoO5 crystal by the vertical Bridgman method is reported in this paper. According to the accurate stoiehiometrie composition, the feed material was synthesized by solid-state reaction. In the Bridgman growth, the furnace temperature was controlled at 1050 - 1070℃ and the temperature gradient near solid-liquid interface was adjusted at 30 - 40℃/cm. Using the crucible lowering rate in the range of 0.6- 1.0 mm/h, transparent large size crystal has been grown successfully by the modified Bddgman process. The crystal was characterized by XRD, DTA/TG and spectral measurement. With X-ray single crystal diffraction, the crystal was verified to be crystallized in monoelinie system with space group of C2/m. The DTA/TG curves show that the crystal is melted congruently at 958℃ and the composition in the melt volatilizes seriously above the temperature. The crystal has a high optical transmission in the visible wavelength range, in which the absorption edge is around 370 nm.