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研究磁性半导体中负磁电阻产生机理对正确理解载流子与磁性离子间的sp-d磁交换作用是非常重要的.通过变温(10—300 K)磁输运和变温(5—300 K)磁化率实验研究了一系列不同Mn含量非简并p型Hg_(1-x)Mn_xTe单晶(x>0.17)的负磁电阻和顺磁增强效应.实验结果表明其负磁电阻与温度的关系和磁化率与温度的关系基本一致,两者都包含一个呈指数型变化的温度函数exp(-K/T).根据磁性半导体的杂质能级理论,非简并P型Hg_(1-x)Mn_xTe单晶在低磁场范围内出现负磁电阻效应的主要物理机理为外磁场的磁化效应使得受主杂质或受主型束缚磁极化子的有效电离能减小.
It is very important to study the mechanism of negative magnetoresistance in magnetic semiconductors to understand the effect of sp-d magnetic exchange between carriers and magnetic ions.By variable temperature (10-300 K) magnetic transport and variable temperature (5-300 K) Magnetic susceptibility experiments of a series of negative magnetoresistance and paramagnetic enhancement effect of a series of non-degenerate p-type Hg_ (1-x) Mn_xTe single crystal with different Mn content (x> 0.17) .Experimental results show that the relationship between negative magnetoresistance and temperature and The relationship between magnetic susceptibility and temperature is basically the same, and both of them contain an exponential temperature function, exp (-K / T). According to the impurity level theory of magnetic semiconductors, the non-degenerate P type Hg_ (1-x) Mn_xTe The main physical mechanism of the negative magneto-resistive effect of the single crystal in the low magnetic field is that the magnetization effect of the external magnetic field decreases the effective ionization energy of the acceptor-dependent or acceptor-bound bounding magnetic polarizer.