Electric and magnetic properties of nano-structure films produced by computer controlled pulse electrodeposition

脉冲电沉积是一种有用的技术，它可以通过调节脉冲振幅和宽度来实现对铁磁薄膜的层组成、多层厚度和克尺寸的原子级控制。通过改变阶跃脉冲波，可以从含有两种以上金属离子的单一电解溶液中制备具有多种磁性能的铁磁薄膜。本文尝试用计算机控制脉冲电沉积的方法，将铁磁性Co层和非磁性Au、Ag层结合在一起，制备铁磁性纳米结构多层膜。我们研究了各种多层薄膜在原子水平上的磁性和磁阻效应之间的关系。磁阻效应取决于Co铁磁层和Ag、Au非磁性层的厚度。这些薄膜的磁化强度随银层和金层厚度的变化呈现最小值。显示MR比最大值的Ag和Au层厚度不一定与显示最小磁化率的Ag和Au层厚度一致。磁自旋的反平行排列是产生多层膜GMR的必要条件，但不是充分条件。对于Co/Au多层膜，显示最小磁化强度的Au层厚度向Au层厚度的较高一侧移动。

Pulse electrodeposition is a useful technique with which it is possible to achieve atomic-scale control of the layer composition, thickness of the multilayer and the gram size in ferromagnetic films by regulating the pulse amplitude and width. It is possible to produce ferromagnetic films with various magnetic properties from a single electrolytic solution containing more than two kinds of metallic ions, by changing the step pulse wave.We attempted to fabricate ferromagnetic nano-structure multilayer films with the combination ferromagnetic Co layers, and non magnetic layer Au and Ag by computer controlled pulse electrodeposition method.We have investigated the relationship between the magnetism and the magnetoresistance effect in the various multilayer films of the atomic level. The magnetoresistance effect is dependent on both the thickness of Co ferromagnetic layer and Ag,Au non-magnetic layers. The magnetization of these films shows the minimum value against the Ag and Au layer thickness. The Ag and Au layer thickness showing the maximum of MR ratio is not of necessary in agreement with the Ag and Au layer thickness showing the minimum of magnetization. Antiparallel alignment of magnetic spin is a necessary but not sufficient condition in order to generate the GMR of multilayer films. For the Co/Au multilayer films, the Au layer thickness showing the minimum of the magnetization shifts to higher side of the Au layer thickness.