Thickness effects on magnetic properties and ferromagnetic resonance in Co-Ni-Fe-N soft magnetic thin films

Abstract

In this study, the magnetic properties and microstructures have been investigated in Co-Ni-Fe-N soft magnetic thin films with various film thicknesses (0.01-1.0 mum). As the film thickness decreases, the coercivity, electrical resistivity, and magnetic anisotropy field of these films increases from 1.1 to 7.9 Oe, 53 to 188 muOmega cm, and 20 to 70 Oe, respectively. In addition, excellent high frequency characteristics were achieved in Co-Ni-Fe-N films with thicknesses less than 0.3 mum, where an effective permeability of, similar to1000 was maintained out to 700 MHz. Analysis results from XRD, TEM, and FMR show that a 0.1-mum-thick film is composed of an amorphous phase. This amorphous phase gradually changes to a crystalline phase with increasing film thickness. (C) 2002 American Institute of Physics.