The effect of the capping layer Ru to the magnetic layer NiFe in magnetic multilayers

This paper is mainly about the magnetic properties of NiFe thin films when using different cap layers such as Ta,Ru.We observed that there appear dead layers at interface NiFe/Ta and NiFe/ Ru.The thickness of dead layers are(1.5±0.2)nm,(1.2±0.2)nm respectively(experimental error within 0.2nm).Although it can not be avoided the appearance of the mixing layers namely dead layers while using two kinds of capping layers,but we found that the thickness of dead layer using Ru as capping layer is less than the thickness of dead layer when using Ta as capping layer.For further confirmation of this result,we used X-ray diffraction method,X-ray photo electron spectrum instrument and investigated this two kinds of thin films.Besides we analysed the computer fitting curve of Ta4f and Ru3d high resolution XPS spectrum using XPS Peak 4.1 fitting software.As a result,we confirmed that Ru is good candidate for being capping layer than Ta in spin electron devices.