Effects of a thin Mg layer on the structural and magnetoresistance properties of CoFeB/MgO/CoFeB magnetic tunnel junctions
Effects of a thin Mg layer on the structural and magnetoresistance properties of CoFeB/MgO/CoFeB magnetic tunnel junctions
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DOI：
10.1063/1.2819530
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发表时间：
2007-11-26
影响因子：
4
通讯作者：
Demailles, D.
中科院分区：
文献类型：
--
作者：
Lu, Y.;Deranlot, C.;Demailles, D.
我们结合了原位反射高能电子衍射、高分辨电子显微镜和磁输运实验，研究了在标准溅射系统中生长的磁性隧道结中插入的薄镁层对氧化镁势垒晶体织构的影响。研究发现，2~6埃的超薄镁层在任何退火前都能有效地促进(001)织构的形成。对于较厚的镁层，由于镁的六方结构，使其(001)织构退化。对于隧道磁阻(TMR)，在400℃退火后，由镁层诱导的氧化镁结晶的有效作用显现出来。在室温下(3K时)TMR为120%的4埃插入镁层是最佳的，而对于完全(001)取向的磁性隧道结，TMR可以显著提高。(C)2007年美国物理研究所。(C)2007年美国物理研究所。
We have combined in situ reflection high energy electron diffraction, high-resolution transmission electron microscopy, and magnetotransport experiments to investigate the role of a thin inserted Mg layer on the crystalline texture of MgO barriers in magnetic tunnel junctions grown in a standard sputtering system. It was found that an ultrathin Mg layer of 2-6 angstrom can efficiently promote a MgO (001) texture prior to any annealing. For thicker Mg layers, the MgO (001) texture was found to degrade due to the hexagonal structure of Mg. For tunneling magnetoresistance (TMR), the efficient role of the MgO crystallization induced by the Mg layer appears after a 400 degrees C annealing. The optimum was found for a 4 angstrom inserted Mg layer with a TMR of 120% at room temperature (210% at 3 K) which could be considerably improved for fully (001) oriented magnetic tunnel junctions. (c) 2007 American Institute of Physics. (c) 2007 American Institute of Physics.