Magnetic Properties of Fe-Al-Si Sputtered Films

Whereas Fe-Al-Si film of composition 5.5 percent Al-9.5 percent Si-remainder Fe (Sendust composition range) has a high permeability and good soft magnetic properties, the sensitivity of the latter to composition changes presents difficulties as regards film formation. The authors studied another promising composition range, 2.5 percent Al-5.5 percent Si-remainder Fe, sputtering films in this range on quartz substrates. Films obtained had smaller coercivities than Sendust films, near-zero magnetostriction, similar to Sendust, and a large in-plane uniaxial anisotropy. This composition borders on a disordered and an ordered phase, suggesting that film properties may be influenced greatly by annealing and other treatment.