Co-Ag/Ag多层膜的巨磁电阻效应

GIANT MAGNETORESISTANCE EFFECT IN Co-Ag/Ag MULTILAYERS

用离子束溅射法制备了６个系列的ＣｏｘＡｇ１００－ｘ／Ａｇ颗粒多层膜，对其巨磁电阻随成分及Ａｇ层和Ｃｏ—Ａｇ层厚度的变化规律进行了研究．当Ａｇ层厚度改变时，ＧＭＲ有一峰值，且随着Ｃｏ含量增加，峰值向层厚增加的方向位移，当Ｃｏ—Ａｇ层厚度改变时，Ｃｏ含量较高的样品的磁电阻在ｄｍ＝２．０ｎｍ附近有一个极大值，而Ｃｏ含量较低的样品在ｄｍ６．０ｎｍ范围是单调上升的．用磁层间静磁相互作用的反铁磁耦合模型对上述现象加以解释．还研究了Ｃｏ４５Ａｇ５５／Ａｇ多层膜样品的退火效应．

Six series of Co xAg 100-x /Ag multilayers have been prepared by an ion beam sputtering system. The giant magnetoresistance effect of the multilayers with different Co contents was studied. With increasing Ag layer thickness the magnetoresistance ratio ΔR/R first increases to maximum and then decreases. It is significant to find that with increasing Co content the maximum shifts towards large Ag layer thickness. These phenomena can be attributed to the antiferromagnetic coupling between the Co clusters in neighboring magnetic layers. For Co-Ag/Ag multilayers with small Co content, ΔR/R increases monotonically with Co-Ag layer thickness, but has a maximum for large Co contents. The annealing effect of Co 45 Ag 55 /Ag multilayers was also studied.