Temperature dependence of tunnel resistance for CoFeB∕MgO∕CoFeB magnetoresistive tunneling junctions: The role of magnon
Temperature dependence of tunnel resistance for CoFeB∕MgO∕CoFeB magnetoresistive tunneling junctions: The role of magnon
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CoFeB∕MgO∕CoFeB 磁阻隧道结隧道电阻的温度依赖性：磁振子的作用
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
H. Yoda
中科院分区：
文献类型：
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作者：
S. Ikegawa;H. Aikawa;T. Ueda;M. Nagamine;N. Shimomura;M. Yoshikawa;K. Hosotani;H. Yoda
隧道电阻的CoFeB scinMgO scinCoFeB结的各种电阻已被研究作为偏置电压Vb和温度的函数，以阐明偏置电压的磁阻比的依赖性。与传统的NiFe scinAlOx scinCoFe结的比较也进行了讨论。在平行排列的磁矩与MgO的障碍的情况下，Vb的依赖性是远远小于反平行（AP）与MgO的障碍和两个对齐与AlOx的障碍。这可能源于MgO势垒的独特隧穿机制：Δ1电子态的相干隧穿。在AP与MgO势垒对准的情况下，观察到显著的特征：隧道电阻的温度系数随着Vb的绝对值的增加而急剧下降，在−0.2V<Vb<0.2V。这表明非弹性隧穿与磁振子模式的激发起着至关重要的作用。
Tunnel resistance for CoFeB∕MgO∕CoFeB junctions with a wide variety of resistance has been investigated as a function of bias voltage Vb and temperature to elucidate bias voltage dependence of the magnetoresistance ratio. Comparison with a conventional NiFe∕AlOx∕CoFe junction is also discussed. In the case of a parallel alignment of the magnetic moments with a MgO barrier, the Vb dependence was much smaller than that of the antiparallel (AP) alignment with a MgO barrier and of both alignment with an AlOx barrier. This probably originates from the unique tunnel mechanism with a MgO barrier: coherent tunneling of Δ1 electron states. In the case of AP alignment with a MgO barrier, distinctive features were observed: temperature coefficient of tunnel resistance steeply decreased with increasing absolute value of Vb at −0.2V<Vb<0.2V. This suggests that inelastic tunneling with excitation of magnon modes plays a crucial role.