Resistivity minima and Kondo effect in ferromagnetic GaMnAs films
Resistivity minima and Kondo effect in ferromagnetic GaMnAs films
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DOI：
10.1063/1.2108131
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发表时间：
2005-10
影响因子：
4
通讯作者：
Hongtao He;Chu-Shou Yang;W. Ge;Jiannong Wang;X. Dai;Yuqi Wang
中科院分区：
文献类型：
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作者：
Hongtao He;Chu-Shou Yang;W. Ge;Jiannong Wang;X. Dai;Yuqi Wang
在2k至290k范围内测量了铁磁GaMnAs，生长或低温退火样品的电阻率的温度依赖性。每个样品的电阻率最小值在相应的温度TM约10K时观察到。在TM以下，电阻率αln(T)与温度呈对数关系，α在9T以下与外磁场无关。这种行为可以用GaMnAs样品中Mn间隙的存在引起的近藤效应来解释。此外，在TM和居里温度（TC）之间的温度范围内，电阻率具有明确的t平方依赖关系，这归因于单磁振子散射。
The temperature dependence of the resistivity of ferromagnetic GaMnAs, as-grown or low-temperature-annealed samples is measured from 2to290K. A resistivity minimum is observed with a corresponding temperature TM around 10K for each sample. Below TM, the resistivity exhibits logarithmic temperature dependence, as αln(T), and α is independent of the external magnetic field up to 9T. Such behavior is explained in terms of the Kondo effect arising from the presence of Mn interstitials in the GaMnAs samples. In addition, a well-defined T-squared dependence of resistivity is found in the temperature range between TM and the Curie temperature (TC), which is attributed to single magnon scattering.