Ni_(81)Fe_(19)/Ni_(100-x)Mn_x双层膜的交换偏置对Ni_(100-x)Mn_x层Mn成分和厚度的依赖  

The dependence of exchange bias of Ni_(81)Fe_(19)/Ni_(100-x)Mn_x bilayers on the Mn content and the thickness ofNi_(100-x)Mn_x

作　　者：代波[1] 蔡建旺[1] 赖武彦[1] 

机构地区：[1]中国科学院物理研究所磁学国家重点实验室,北京100080

出　　处：《物理学报》2003年第2期478-482,共5页Acta Physica Sinica

基　　金：国家自然科学基金重大项目 (批准号 :19890 3 10 )资助的课题~~

摘　　要：通过调整Mn的成分 ,系统地研究了Ni81 Fe1 9 Ni1 0 0 -xMnx 双层膜的磁学性质 ,特别是交换偏置场 (Hex)的变化 .当Ni1 0 0 -xMnx 中Mn的原子百分比在 5 3 4 %到 6 0 0 %之间时 ,对于 15 0nm的Ni81 Fe1 9,得到了最大的交换偏置场17 5kA m ,同时由于Mn对Ni81 Fe1 9层的扩散所造成的磁矩的降低小于 2 0 % ;高角x射线衍射证明Ni1 0 0 -xMnx 的晶格常数随着Mn成分的改变而变化 ,Mn含量越多 ,其晶格常数越大 ;制备态Ni1 0 0 -xMnx 膜晶格常数与θ相NiMn膜晶格常数的接近程度与NiMn膜θ相形成的容易程度相对应 .也研究了交换偏置场随着Ni1 0 0 -xMnx 厚度的变化 ,第一次得到了当Ni1 0 0 -xMnx 中Mn的原子百分比为 70 6 %时 ,Ni81 Fe1 9(15 0nm) Ni1 0 0 -xMnx(9 0nm)双层膜在经过 2 4 0℃ ,5h退火后 ,可以有 8 0kA m的交换偏置场 ,此时铁磁层磁矩的大小几乎不变 .By adjusting the Mn concentration, we systematically investigated the magnetic properties, especially the exchange bias field (H-ex) in Ni-81 Fe-19/Ni100 - x Mn-x bilayers. In the range of 53.4 less than or equal to x less than or equal to 60.0, the largest exchange bias field( similar to 17.5kA/m)was achieved,and at the same time the reduction of magnetic moment due to the Mn diffusion into the Ni81Fe19 layer was lower than 20%. High-angle x-ray diffraction( XRD) showed a variation of Ni-100 (-) Mn-x(x) lattice parameters when altering the Mn content: the more the Mn content, the larger the lattice parameters. It was found that the as-deposited Ni100 - Mn-x(x) films with their lattice parameters close to those of theta-phase of NiMn alloy could be transformed into theta-phase relatively easily. Finally, the exchange bias of the bilayers with different Ni100 - xMnx thicknesses was studied. We first obtain a 8.0 kA/m exchange bias field in the Ni81Fe19 (15.0nm)/Ni-100 (-) Mn-x(x) (9.0nm) bilayers when Mn content increases to 70.6% after annealed at 240degreesC for 5 h, while the magnetic moment of the ferromagnetic layer was nearly unichanged.

关 键 词：Ni81Fe19/Ni100-xMnx双层膜 厚度 交换偏置场 自旋阀 锰 成分 磁学性质 铁磁材料 反铁磁材料 

分 类 号：O484.43[理学—固体物理] TM27[理学—物理]