钇铝石榴石晶体高压相变研究

采用金刚石压砧高压设备,对立方结构掺钕钇铝榴石多晶进行高温高压相变研究。实验分同时加温加压、独立加压、独立加温三类。对压力温度作用后相变产物进行了 X 射线衍射研究,对相变前后样品的配位数、晶体结构、晶胞参数、体积、密度进行了对比。

HIGH PRESSURE PHASE TRANSFORMATION OF YTTRIUM ALUMINUM GARNET

Phase behaviour of Nd:YAG have been studied in the diamondanvil cell employing YAG laser heating from 10 to 52.6 GPa and at the temperature from room temperature to 2000 C, and in the six anvil pressure vessel from 1300 C to 1500 C temperature and at about 6 GPa pressure. Phase transformation of Nd:YAG was presented. Nd:YAG transform to (Y Nd) A10 with perovskite structure at pressure 3.8 GPa and great than this, temperature at 1100 C. The phase transformation crystal formula is:(Y, Nd)AlO........3(Y, Nd)AlO + A1O.The new phase are still stable until pressure up to 37.8 GPa and 1000 C. High pressure is advantage for increase density from YAG 4.55 g/cm to YA10 5.35 g/cm and for rising coordination of Al, the lattice parameter decrease from YAG a = 11.990 A to YA10 a = 5.200, b = 5.333,c = 7.392 A. The mole volume decnases 10%.Phase behaviours of Fe Al (SiO) also have been studied in the six anvil pressure vessel, the pressure and temperature at about 6 GPa and 1300 C no phase transformation has been found. The more detail experimental results are discussed.