The magnetic properties of Co-Ni-Fe films

Hₖ , ₖ ,α₉₀and Hchave been measured for vapor-deposited nonmagnetostrictive Co-Ni-Fe films, 1500 Å thick. All parameters except Hchave been measured using the transverse-biased permeability apparatus. Hkincreases linearly with cobalt melt content up to 15-percent cobalt,ₖand Hcincrease with increasing cobalt and substrate temperature. α90decreases in the region 0-15-percent cobalt and then increases with increased cobalt melt content and substrate temperature. The coefficient of magnetoelastic composition sensitivitySis the slope of the curve η versus the ratio of nickel to iron in the melt for a constant cobalt percentage about the pointη = 0. The value ofSincreases rapidly with substrate temperature to a maximum near 300°C if the cobalt percentage is small. For larger amounts of cobaltSis reduced and is more independent of temperature. It is proposed that the volume fraction and the mobility of the grain boundaries in the film structure are primarily responsible forS.