Microstructure and magnetoelastic properties of FeCo/Ag multilayers

There is growing evidence that in magnetic films of thickness less than 20 nm there can be significant change in the values of magnetic anisotropy con stant and magnetoelastic coupling from those of bulk materials. While pheno menological models based on Neel's idea of surface anisotropy may offer a p artial explanation, it is vital to develop a more mechanistic understanding . Recently the potential contribution of interface and surface strains to t he observed property change has been highlighted. Here we report the field emission gun TEM and electron spectroscopic images of the structure of the interface region between Fe50Co50 and Ag, the local crystallographic textur e and the distribution of Ag in magnetostrictive Fe50Co50/Ag multilayers. T he results are correlated with the bulk measurements of coercivity and the saturation magnetostriction constant. For the first time it is possible to provide a degree of microstructural interpretation of the magnetic data. (C ) 2001 American Institute of Physics.