Oxidation and Annealing Process : Morphological Change and Nanocontact MR in Spin Valves With FeCo-AlOx NOL Spacer
Oxidation and Annealing Process : Morphological Change and Nanocontact MR in Spin Valves With FeCo-AlOx NOL Spacer
复制标题
氧化和退火过程：带有 FeCo-AlOx NOL 间隔物的旋转阀中的形态变化和纳米接触 MR
DOI：
10.1109/tmag.2011.2157110
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发表时间：
2011
影响因子：
2.1
通讯作者：
他
中科院分区：
文献类型：
--
作者：
塩川陽平;他
我们通过原位导电原子力显微镜（c-AFM）研究了薄AlOx纳米氧化物层（NOL）中直径约为1-2 nm的铁磁纳米接触（NC）的形成机制，这是唯一适合测量这种小特征的形态变化的方法。通过离子辅助氧化（IAO）法在1.3 nm厚的Al上制备的Fe0.5Co0.5NCs自旋阀（SV）具有纳米接触磁电阻（NCMR）特性，对于1 Ω μm2，MR比为5%。根据c-AFM的测量，这些纳米颗粒主要位于AlOx颗粒之间的山谷或颗粒的边缘。也就是说，纳米碳是在IAO对Al的氧化和凝聚过程中形成的。此外，我们发现高温退火工艺将0.5 Ω μm2的MR比提高到约10%。高温退火过程可能涉及AlOx的形态变化，并导致NC中的Al原子通过与作为杂质的氧结合而迁移到AlOx。其次，铝的形态变化和迁移导致纳米碳的电阻率低，长度短。
We studied the formation mechanism of ferromagnetic nanocontacts (NCs) around 1-2 nm in diameter in thin AlOxnano-oxide layer (NOL) through in situ conductive atomic force microscopy (c-AFM), which is the only method suitable for measuring morphological changes in features this small. Spin valves (SVs) with Fe0.5Co0.5NCs in AlOxNOL fabricated by ion-assisted-oxidation (IAO) irradiated onto 1.3-nm-thick Al had nanocontact magnetoresistance (NCMR) characteristics with the MR ratio of 5% for 1 Ω μm2. According to measurements with c-AFM, these NCs were mostly located at the valleys between the AlOxgrains or the edge of the grain. In other words, NCs were formed in the oxidation and cohesion process of Al by the IAO. Moreover, we found that the high-temperature annealing process improved the MR ratio to around 10% for 0.5 Ω μm2. The high-temperature annealing process may involve the AlOxmorphological change and have led the Al atoms in NCs to migrate to AlOxby combining with oxygen as impurities. Then, the morphological changes and migration of Al caused NCs to be the low resistivity and the short length.