Structure and Soft Magnetic Properties of Fe-Ti-M (M=Al,Si,Co) Ternary Films

The magnetic and structural properties of sputtered Fe-Al-Ti, Fe-Si-Ti and Fe-Co-Ti ternary films were investigated. Samples were annealed at 673K for one hour. Crystal structures were bcc for the Fe-Si-Ti and Fe-Co-Ti ternary films, and a mixture of bcc and bcc+Fe₂Ti for the Fe-Al-Ti ternary films. The addition of Ti reduces &3x001F5;rain sizes to a minimum of about 10 nm. Addition of Al, Si or Ti to Fe reduces the saturation magnetic flux density of Fe-Al-Ti and Fe-Si-Ti films, and addition of Co increases the saturation magnetic flux density of Fe-Co-Ti. Zero-magnetostriction samples were obtained in each ternary system. Low coercivity (under 5 Oe) and high initial permeability (about 1000) were obtained together with zero magnetostriction for Fe-Al-Ti ternary films by adding a small amount of Ti. In the case of Fe-Co-Ti ternary films, low coercivity and high permeability were obtained along with small grain sizes of 10 nm or so. Films with low magnetostriction (λ_s≪3×10^-6) had a coercivity roughly proportional to the third power of the grain diameter.