Magnetic and structural properties of permalloy-tantalum multilayer thin films

This work describes a detailed investigation into the magnetic and structural properties of permalloy-tantalum multilayered thin films produced by vacuum evaporation. Their microstructure was investigated using high-resolution TEM and the magnetic properties were measured with vibrating-sample and vibrating-reed magnetometers. The results show a reduction in coercivity for the multilayer films which is independent of the number of layers but depends strongly on the magnetic layer thickness. The tantalum layer is shown to be continuous and microcrystalline down to 25-A thickness, but the interface between the layers is irregular and may give rise to additional magnetostatic coupling as the tantalum layer thickness is reduced