Improvement of the structural and magnetic properties of Permalloy/Gadolinium multilayers with Mo spacers

We have studied the influence of the growth conditions on the structural characteristics of sputtered Py(Fe20Ni80)/ Gd/Py(Fe20Ni80) thin films. Auger electron spectroscopy reveals the existence of Ni in the Gd layer. The Ni concentration profile appears asymmetric with a higher concentration close to the top Py layer. This asymmetrical Ni concentration produces a different coercivity of each Py layer. It is possible to reduce the Ni interdiffusion by using multilayers based on Py/Gd bilayers separated by Mo spacers between the Py/Gd bilayers. In these samples we have obtained an enhancement of the structural and magnetic properties.