Spacer layer properties in antiferromagnetically coupled Fe/SixFe1−x

The antiferromagnetically coupled Fe/SixFe1−x multilayers deposited in UHV by magnetron sputtering onto oxidized Si wafers for different Fe layer thicknesses 0.3 nm < dFe < 4 nm were examined. We showed that both magnetic and electronic properties of the antiferromagnetically coupled Fe/Si Mls are influenced by interfacial mixing between Fe and Si layers. The current-voltage characteristics measured at room temperature, perpendicularly to the multilayer planes allowed us to show the semiconducting character for nominally pure Si layers. We showed that the application of interfacial Co (or Au) thin layers prevented the Fe(Si) interdiffusion into Si(Fe) layers leading to the absence of antiferromagnetic coupling. We found that addition of at least 0.5 nm of Ge in the spacer, introduced either at the Fe/Si interface or in the center of Si spacer destroyed the AF coupling.