Effect of stress on stripe domain onset in sputtered FeAlN and CoFe films

Abstract

Stripe domains caused by perpendicular anisotropy degrade soft magnetic properties of thin films used in recording heads. In this work, the relationship between stress and the susceptibility to stripe domains in soft magnetic thin films is studied theoretically and experimentally. The critical stripe domain onset thickness of a polycrystalline film with cubic unit cell under a planar, isotropic stress is calculated as a function stress and texture for sputtered FeAlN and CoFe films. In good agreement with experimental data, the results show that the stripe domain onset thickness depends on stress and texture. In the sputtered Co65Fe35 film, a residual stress close to zero helps eliminate the possibility of stripe domains, while in the sputtered FeAlN film, the role played by stress depends on texture. For the most frequently seen (110)-textured FeAlN film, large compressive stresses help reduce the possibility of stripe domains for low and moderate N concentrations.