In-Situ Conductivity Measurement of BaF2 under High Pressure and High Temperature  

作　　者：郝爱民 高春晓 李明 贺春元 黄晓伟 张东梅 于翠玲 邹广田 李延春 李晓东 刘景 

机构地区：[1]State Key Laboratory for Superhard Materials, Jilin University, Changchun 130012 [2]Department of Mathematics and Physics, Hebei Normal University of Science and Technology, Qinhuangdao 066004 [3]Beijing Synchrotron Radiation Facility, Chinese Academy of Sciences, Beijing 100039

出　　处：《Chinese Physics Letters》2006年第11期2917-2919,共3页中国物理快报（英文版）

基　　金：Supported by the National Natural Science Foundation of China under Grant Nos 40473034, 40404007, 10574055, and 50532020, and the National Basic research Program of China under Grant No 2005CB724404.

摘　　要：We perform the in-situ conductivity measurement on BaF2 at high pressure using a microcircuit fabricated on a diamond anvil cell. The results show that BaF2 initially exhibits the electrical property of an insulator at pressure below 25 GPa, it transforms to a wide energy gap semiconductor at pressure from 25 to 30 GPa, and the conductivity increases gradually with increasing pressure from 30 GPa. However, the metallization predicted by theoretical calculation at 30-33 GPa cannot be observed. In addition, we measure the temperature dependence of the conductivity at several pressures and obtain the relationship between the energy gap and pressure. Based on the experimental data, it is predicted that BaF2 would transform to a metal at about 87 GPa and ambient temperature. The conductivity of BaF2 reaches the order of 10^-3Ω^-1 cm^-1 at 37 GPa and 2400 K, the superionic conduction is not observed during the experiments, indicating the application of pressure elevates greatly the transition temperature of the superionic conduction.We perform the in-situ conductivity measurement on BaF2 at high pressure using a microcircuit fabricated on a diamond anvil cell. The results show that BaF2 initially exhibits the electrical property of an insulator at pressure below 25 GPa, it transforms to a wide energy gap semiconductor at pressure from 25 to 30 GPa, and the conductivity increases gradually with increasing pressure from 30 GPa. However, the metallization predicted by theoretical calculation at 30-33 GPa cannot be observed. In addition, we measure the temperature dependence of the conductivity at several pressures and obtain the relationship between the energy gap and pressure. Based on the experimental data, it is predicted that BaF2 would transform to a metal at about 87 GPa and ambient temperature. The conductivity of BaF2 reaches the order of 10^-3Ω^-1 cm^-1 at 37 GPa and 2400 K, the superionic conduction is not observed during the experiments, indicating the application of pressure elevates greatly the transition temperature of the superionic conduction.

关 键 词：DIAMOND-ANVIL CELL ELASTIC-CONSTANTS PHASE-TRANSITIONS IONIC-CONDUCTIVITY CRYSTALS FLUORIDE SIMULATIONS DEPENDENCE RESISTANCE SRCL2 

分 类 号：O441.1[理学—电磁学]