反铁磁层厚度对垂直磁各向异性钴/铂/铁锰多层膜磁性质的影响

The effect of the AFM layer thickness on the magnetic properties of Co/Pt/FeMn multilayers with perpendicular magnetic anisotropy

在室温下用超高真空磁控溅射系统制备了一系列的Pt(4.0nm)/[Co(0.5nm)/Pt(0.3nm)]3-FeMn(tAFnm)多层膜样品,研究了反铁磁层厚度对于易轴垂直于样品表面的Co/Pt/FeMn多层膜磁性质的影响。在室温下利用样品的剩磁进行了X射线磁圆二色测量(XMCD),结果表明在铁磁/反铁磁界面有反铁磁层铁锰的净磁矩,这些净磁矩仅来自于铁元素。铁的磁矩倾向于垂直于膜面排列。磁测量结果表明,随着铁锰层厚度的增加,交换偏置场HEB增加直到饱和,而HC先增加,然后轻微减少,在tAF>7.5nm以后,HEB和HC都几乎不变了。没有观察到磁锻炼效应。

A set of Pt(40 nm)/[Co(5 nm)/Pt(3 nm)]3/FeMn(tAF nm)multilayer samples deposited on the Si (100)wafer at room temperature was prepared using an ultrahigh vacuum magnetron sputtering system.We have studied the effect of the AF layer thickness tAF on the magnetic properties of Co/Pt/FeMn multilayer films with out-of-plane magnetic easy axis.X-ray magnetic circular dichroic (XMCD)measurement was performed by using the remnant magnetization of the samples at room temperature.The result shows that the net magnetic moment of the FeMn,which mainly originated from Fe,exists at the FM/AFM interface only,and the moment of Fe tends to be perpendicular to the sample plane.In the results of magnetic measurement,the exchange bias, H EB ,increases gradually and then flatly,meanwhile the coercivity,HC,increases first and then decreases slightly with increment of the FeMn layer thickness.Both HEB and HCare almost unchanged after tAF goes be-yond about 7.5 nm.The training effect has not been observed in the samples.