Cd_(0.95)Fe_(0.05)Te能隙的温度和压力效应

TEMPERATURE AND PRESSURE DEPENDENCE OF THE ENERGY GAP OF Cd_(0.095)Fe_(0.05)Te

采用金刚石对顶砧高压装置测量了半磁半导体Cd_(0.95)Fe_(0.05)Te光吸收边的压力效应,得到其一级和二级压力系数分别为α=8.2×10^(-11)eV/Pa和β=-7.7×10^(-21)eV/Pa^2;测量了不同温度下的Cd_(0.95)Fe_(0.05)Te吸收谱,得到其能隙温度系数为α=-4.4×10^(-4)eV/K。此外,在低温下发现了一个Fe^(2+)吸收峰,根据晶体场理论判定为Fe^(2+)的~5E→~3T_1跃迁吸收峰。

By using the diamond-anvil cell high-pressure equipment, the optical absorption edge of semimagnetic semiconductor Cd_(0.95)Fe_(0.05)Te has been measured under different pressures. The first and second order pressure coefficients of the energy gap of this material, i. e. α=8.2×10^(-11) eV/Pa and β=-7.7×10^(-21) eV/Pa^2, are obtained. The optical absorption spectra of Cd_(0.95)Fe_(0.05)Te at different temperatures have also been measured and the temperature coefficient of the energy gap of this material, α=-4.4×10^(-4)eV/K, is obtained. In addition, at low temperature an absorption peak of Fe^(2+) has been found, which can be attributed to the transition ~5E→~3T_1 in the light of the crystal field theory.