摘要
采用垂直Bridgman法制备出了x =0 1、0 2 2和 0 4的Cd1-xMnxIn2 Te4 晶体 .采用红外透射光谱法研究了晶体的红外光学特性 .用超导量子磁强计测量了样品在温度范围 5～ 30 0K和磁场强度范围 0～ 5T内的磁化强度 .在中红外波段透过率曲线变化很小 .随着x的增加Cd1-xMnxIn2 Te4 的光学带隙移向高能端 .磁化率倒数 χ-1与温度T的关系曲线在高温区服从居里 万斯定律 ,在低温下x≥ 0 2 2时向下偏离该定律 .与具有相同Mn2 + 浓度的Cd1-xMnxTe晶体相比Cd1-xMnxIn2 Te4 晶体的交换积分常数较小 .
A new series of diluted magnetic semiconductor (DMS),Cd_ 1-x Mn_ x In_2Te_4 are successfully synthesized by the vertical bridgman method (VBM) for the first time.The infrared transmission spectra of Cd_ 1-x Mn_ x In_2Te_4 crystals ( x =0.1,0.22 and 0.4) are measured respectively at room temperature.Magnetic susceptibility measurements on the crystals with different compositions are also carried out in the temperature range 5K≤ T ≤300K using a SQUID magnetometer at H =1T.The value of transmittance is almost a constant in 4000～500cm -1 for each crystal,but the energy band gap of Cd_ 1-x Mn_ x In_2Te_4 becomes larger when the composition x increases.The inverse magnetic susceptibilities of Cd_ 1-x Mn_ x In_2Te_4( x ≥0.22) obey Curie-Weiss laws at high temperatures while the curves show down deviation at lower temperatures.Quantitative analysis reveals that the exchange integral constant J_1/k _B is much smaller in Cd_ 1-x Mn_ x In_2Te_4 than that in Cd_ 1-x Mn_ x Te for the same concentration of Mn.
基金
国家自然科学基金 (批准号 :5 9872 0 2 7)
航空科学基金 (批准号 :98G5 30 99)资助项目~~
关键词
稀磁半导体
Cd1-xMnxIn2Te4
红外透过度
磁化率
反铁磁交换作用
DMS
diluted magnetic semiconductor
Cd_ 1-x Mn_ x In_2Te_4
infrared transmission
magnetic susceptibility
magneto-optical effect
anti-ferromagnetic exchange interaction
