Large positive magnetoresistance effects in the dilute magnetic semiconductor (Zn,Mn)Se in the regime of electron hopping
Large positive magnetoresistance effects in the dilute magnetic semiconductor (Zn,Mn)Se in the regime of electron hopping
复制标题
DOI：
10.1063/1.4894236
复制
发表时间：
2014-08
影响因子：
3.2
通讯作者：
F. Jansson;M. Wiemer;A. Nenashev;S. Petznick;P. Klar;M. Hetterich;F. Gebhard;S. Baranovskii
中科院分区：
文献类型：
--
作者：
F. Jansson;M. Wiemer;A. Nenashev;S. Petznick;P. Klar;M. Hetterich;F. Gebhard;S. Baranovskii
研究了稀磁半导体在跳跃输运状态下的磁电阻效应。对掺Cl的Zn_（1-x）Mn_xSe（x < 8%）进行了测量，并与用跳跃输运模型得到的模拟结果进行了比较。Cl供体的能级通过s-d交换相互作用受到附近Mn原子的磁化强度的影响。组成无序，特别是磁性原子的随机分布，导致磁场诱导的施主能量分布的加宽。随着能量分布变宽，电子输运受到阻碍，并且对磁阻产生较大的正贡献。施主能量分布的这种加宽在很大程度上足以解释在n型（Zn，Mn）Se中实验观察到的磁阻效应，其中施主浓度低于金属-绝缘体转变。
Magnetoresistance in dilute magnetic semiconductors is studied in the hopping transport regime. Measurements performed on Cl-doped Zn1–xMnxSe with x < 8% are compared with simulation results obtained by a hopping transport model. The energy levels of the Cl donors are affected by the magnetization of Mn atoms in their vicinity via the s-d exchange interaction. Compositional disorder, in particular, the random distribution of magnetic atoms, leads to a magnetic-field induced broadening of the donor energy distribution. As the energy distribution broadens, the electron transport is hindered and a large positive contribution to the magnetoresistance arises. This broadening of the donor energy distribution is largely sufficient to account for the experimentally observed magnetoresistance effects in n-type (Zn,Mn)Se with donor concentrations below the metal–insulator transition.