Magnetic properties of oblique-evaporated Co-Ni thin films

Abstract

Co 1 - x Ni x ( x = 0, 0.2 and 0.3) thin films of thickness about 1500 Å were electron-beam evaporated onto silicon and polymide substrates at various oblique angles α. In-plane coercivities and squareness ratios both along and transverse to the incidence plane were examined. Also, the angular variations of coercivity of films prepared at α = 0 ° to 85 ° were investigated. The magnetic anisotropy changes from an in-plane anisotropy with the easy axis perpendicular to the incidence plane to an out-of-plane anisotropy parallel to the incidence plane, the transition occuring at about 60 °. Also discussed is the effect of the substrate temperature on the magnetic properties and columnar microstructure of the oblique-evaporated films. At room temperature, there is a small drop in coercivity at α = 60 ° before a sharp rise in coercivities to 1400 Oe as the oblique angle increases.