【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 .更多还原

【Abstract】 By adjusting the Mn concentration,we systematically investigated the magnetic properties,especially the exchange bias field( H ex ),in Ni 81 Fe 19 /Ni 100- x Mn x bilayers.In the range of 53 4≤ x ≤60 0,the largest exchange bias field(～17 5kA/m)was achieved,and at the same time the reduction of magnetic moment due to the Mn diffusion into the Ni 81 Fe 19 layer was lower than 20%.High angle x ray diffraction(XRD)showed a variation of Ni 100- x Mn 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 Ni 100- x Mn x films with their lattice parameters close to those of θ phase of NiMn alloy could be transformed into θ phase relatively easily.Finally, the exchange bias of the bilayers with different Ni 100- x Mn x thicknesses was studied.We first obtain a 8 0 kA/m exchange bias field in the Ni 81 Fe 19 (15 0nm)/Ni 100- x Mn x (9 0nm)bilayers when Mn content increases to 70 6% after annealed at 240℃ for 5h,while the magnetic moment of the ferromagnetic layer was nearly umchanged.更多还原