Abstract: Giant Faraday rotation as a function of photon energy andcomposition for Cd_1-xMn_xTe and Cd_1-xFe_xTe in temperature range 70K to 300K has been measured by using extinction, alternating magnetic field and magneto-optical modulation methods. Faraday rotation angles are negative and a single-oscillator model fit the data very well for Cd_1-xMn_xTe with relatively high compositions (x ≥0.1). It is shown that Cd_1-xFe_xTe crystals exhibit the same order giant Faraday rotation cha-racteristic as Cd_1-xMn_xTe. With relatively low composition x, Faraday rotation angles vary from positive to negative when photon energy closeto the band gap edge, a multioscillator model has been successfully usedto explain the data. Alternating magnetic field method is found to be the best one in this region, however, magneto-optical modulation methodtakes advantages of its high accurate for thin samples or under low magnetic field.

Key words: diluted magnetic semiconductors, faraday effect, magneto-optical-modulation

摘要： 用消光法、交替磁场法和磁光调制法测量了不同温度下、不同组分的稀磁半导体Cd_1-xMn_xTe和Cd_1-xFe_xTe的巨法拉第效应。实验表明：对较高组分的Cd_1-xMn_xTe（x ≥0.1），法拉第旋转角为负，用单振子模型能很好地描述实验结果。稀磁半导体Cd_1-xFe_xTe表现出与Cd_1-xMn_xTe同量级的巨法拉第效应，当组分较低时，法拉第旋转角随入射光子能量出现由正到负的变化，必须用多振子模型才能很好解释实验结果。当样品很薄或磁场较低时，磁光调制法以其很高的测量精度显示出巨大的优越性。

关键词: 稀磁半导体, 法拉第效应, 磁光调制