NiFe/NiO bilayers with high exchange coupling and low coercive fields
NiFe/NiO bilayers with high exchange coupling and low coercive fields
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DOI：
10.1063/1.364964
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发表时间：
1997-04
影响因子：
3.2
通讯作者：
De‐hua Han;J. Zhu;J. Judy
中科院分区：
文献类型：
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作者：
De‐hua Han;J. Zhu;J. Judy
NiO/Ni_（81）Fe_（19）双层膜具有高交换耦合Hex和低介电常数Hc。通过改变射频反应溅射条件，在Si（100）晶片上沉积了具有（111）、（200）和（220）织构以及不同表面/界面粗糙度的NiO双层膜。一个新的参数的交换耦合的比，Hex/Hc，被用来量化的双层膜的交换偏置的有效性。从NiO（45 nm）/NiFe（10 nm）双层膜获得Hex=39 Oe和Hc=4.1 Oe，得到Hex/Hc=9.51的比率，这显著高于任何先前报道的结果。原子力显微镜研究表明，NiO/NiFe双层膜表面粗糙度的降低是导致低介电常数的关键.提出了NiFe膜中的粗糙度引起的静磁耦合可能是NiO交换偏置NiFe双层膜中相关高矫顽力的主要机制之一。制备了NiO/NiFe/Co/Cu/Co/NiFe自旋阀薄膜，并对薄膜的结构进行了表征。
NiO/Ni81Fe19 bilayers with high exchange coupling, Hex, and low coercivity, Hc, were fabricated. These bilayers with NiO crystalline textures of (111), (200), and (220), and different surface/interface roughness were deposited onto a Si(100) wafer by changing the rf reactive sputtering conditions. A new parameter of exchange coupling to coercivity ratio, Hex/Hc, was used to quantify the effectiveness of the exchange bias for the bilayer film. An Hex=39 Oe and Hc=4.1 Oe were obtained from a NiO (45 nm)/NiFe (10 nm) bilayer, yielding a ratio of Hex/Hc=9.51, which was significantly higher than any previously reported results. An atomic force microscopy study showed that the key to the low coercivity was the reduction of surface roughness of the NiO/NiFe bilayer. It is proposed that the roughness-induced magnetostatic coupling in the NiFe film could be one of the main mechanisms for the relating high coercivity in NiO exchange-biased NiFe bilayer. NiO/NiFe/Co/Cu/Co/NiFe spin-valve films were deposited and a g...