Inverse magnetoresistance in magnetic tunnel junction with an Fe/sub 3/O/sub 4/ electrode
Inverse magnetoresistance in magnetic tunnel junction with an Fe/sub 3/O/sub 4/ electrode
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DOI：
10.1109/tmag.2005.855294
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发表时间：
2005-04
影响因子：
2.1
通讯作者：
C. Park;J. Zhu;Y. Peng;D. Laughlin;R. White
中科院分区：
文献类型：
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作者：
C. Park;J. Zhu;Y. Peng;D. Laughlin;R. White
采用等离子体氧化铁电极的磁性隧道结（MTJ）已经用标准光刻法在氧化硅晶片上制备。高分辨透射电子显微镜（HRTEM）和衍射图表明，在可控氧等离子体作用下，薄Fe层可以被氧化成纯Fe/sub 3/O/sub 4/，而不含其它晶相，如FeO和Fe/sub 2/O/sub 3/。为了生长与AlOx阻挡层直接接触的Fe/sub 3/O/sub 4/，我们从1.8至5 nm的Fe层开始。结果发现，完全氧化只发生在1.8 nm的厚度。在室温和低温（110 K）下测量了MTJ的磁和电输运性质。当与AlOx势垒相邻的层为Fe/sub 3/O/sub 4/时，观察到逆磁阻（MR）行为，这是从Fe/sub 3/O/sub 4/的能带结构所预期的。然而，当游离铁存在，由于不完全氧化，观察到积极的MR行为。
Magnetic tunnel junctions (MTJ) with a plasma-oxidized Fe electrode have been fabricated on oxidized silicon wafers with standard photolithography. High-resolution transmission electron microscopy (HRTEM) and diffraction patterns show that a thin Fe layer can be oxidized by a controlled oxygen plasma into pure Fe/sub 3/O/sub 4/ without other crystallographic phases such as FeO and Fe/sub 2/O/sub 3/. To grow Fe/sub 3/O/sub 4/ directly in contact with an AlOx barrier, we began with Fe layers that varied from 1.8 to 5 nm. It was found that complete oxidation only occurred for the 1.8-nm thickness. Magnetic and electrical transport properties on the MTJs were measured at room temperature and low temperature (110 K). When the layer adjacent to the AlOx barrier was Fe/sub 3/O/sub 4/, inverse magnetoresistance (MR) behavior was observed, which is what is expected from the band structure of Fe/sub 3/O/sub 4/. However, when free Fe exists due to incomplete oxidation, positive MR behavior is observed.