GdOBr∶Eu晶场参数与自由离子参数的高压研究  

HIGH PRESSURE STUDY ON CRYSTAL FIELD PARAMETERS AND FREE ION PARAMETERS FOR GdOBr∶Eu

作　　者：李宏年[1,2,3] 池元斌[1,2,3] 王立中 刘慎薪[1,2,3] 徐亚伯 

机构地区：[1]浙江大学物理系 [2]吉林大学超硬材料国家重点实验室 [3]中国科学院长春物理研究所

出　　处：《物理学报》1997年第4期702-714,共13页Acta Physica Sinica

摘　　要：在ＧｄＯＢｒ∶Ｅｕ的常压和高压荧光谱实验数据基础上，对晶场能级及其重心进行了拟合计算，得到了晶场参数和自由离子参数（Ｓｌａｔｅｒ参数和自旋轨道耦合参数）在高压下的变化情况．计算结果表明，随压力增大，晶场参数Ｂ４０，Ｂ６０增大，Ｂ６４减小，Ｂ２０，Ｂ４４的变化有些起伏．晶场强度在８ＧＰａ以下随压力增大而减弱，其后开始变强，但在实验压力范围内未能达到常压下的数值．自旋轨道耦合参数在高压下的变化与晶场强度相似，Ｓｌａｔｅｒ参数Ｅｉ（ｉ＝１—３）对于不同的ｉ其变化趋势不同，Ｅ１∶Ｅ２∶Ｅ３与类氢比率相近，但随压力有一定的起伏．为了揭示晶场参数和自由离子参数的这些变化所包含的物理内容，文中还与其随ＲＥＯＢｒ（ＲＥ＝Ｙ，Ｇｄ。Abstract Simulation of crystal field levels and the barycenters are conducted, based on the fluorescence spectra of GdOBr∶Eu under ambient and high pressures. Calculated results are concide with experimental results very well. Variations of Slater and spin orbit parameters with pressure are obtained. With pressure increasing, B 4 0, B 6 0 increase, B 6 4 decreases, and B 2 0 and B 4 4 show some what fluctuating variations. Strength of the crystal field decreases with increasing pressure from 0GPa to about 8GPa, then increases slightly until 12GPa. Variation of spin orbit parameter is similar to that of crystal field strength. Slater parameters E i(i=1—3) show different variations for different i under pressures. E 1∶E 2∶E 3 is little short of the value of hydrogenic ratio, but varies slightly with increasing pressure. To reveal physical significance in the variations of these parameters, comparison with variations with different hosts are made.

关 键 词：镧系离子 高压 晶场系数 自由离子 

分 类 号：O614.33[理学—无机化学]