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为探索稀土材料Eu2Fe14B在磁性隧道结中的应用,利用密度泛函理论和非平衡态格林函数方法研究了Eu2Fe14B/MgO/Eu2Fe14B磁性隧道结。计算了双铁磁电极平行和反平行磁化配置下,隧道结在0～1.5 V偏压下的电流和传输谱等电子传输特性。分析了两种结构下不同自旋电流的特性,并根据零偏压下的传输谱结果分析了这两种结构的电流差异。由磁性隧道结在此偏压范围内伏安特性曲线和总电导特性的计算结果,得到了隧穿磁电阻(TMR)。分析了这种磁性隧道结中出现的隧穿磁电阻随偏压的增大产生的振荡和反转现象,得出隧穿磁电阻出现反转是Eu的d电子的负自旋极化引起的。
Abstract：In order to research the application of the rare earth material Eu2Fe14B in the magnetic tunnel junction(MTJ),the magnetic tunnel junction Eu2Fe14B/MgO/Eu2Fe14B was investigated with the density function theory and the non-equilibrium Green's function.The electronic transport properties such as the current and transmission spectrum were calculated under the bias vol-tage of 0-1.5 V,where the two ferromagnetic electrodes were configured for the parallel magnetization and anti-parallel magnetization.The characteristics of the spin-up current and spin-down current were studied.Then the current differences of the two different configurations were analyzed,according to the transmission spectrum when the zero voltage was applied to the junction.The tunneling magnetoresistance(TMR) was obtained by calculating the characteristics of the I-V curve and total conductance in the bias voltage range for the magnetic tunnel junction.The oscillation and inversion for the tunneling magnetoresistance of the Eu2Fe14B/MgO/Eu2Fe14B magnetic tunnel junction with the increase of the voltage were analyzed.The results show that the inversion results from the negative spin polarization of the d electrons in Eu.
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基本信息:
中图分类号:O469
引用信息:
[1]黄沈杰,刘宇扬,胥海波,等.稀土材料铕铁硼磁性隧道结的第一性原理研究[J].微纳电子技术,2013,50(03):151-155.
基金信息:
国家自然科学基金资助项目(11005050)
2013-03-15
2013-03-15