Magnetic anisotropy of permalloy thin film on Mo stepped surface

• Published in: Journal of magnetism and magnetic materials 2002-02, Vol.239 (1), p.17-21
• Main Authors: Fu, C.M., Kao, P.C., Tsai, M.S., Hsu, H.S., Yu, C.C., Huang, J.C.A.
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Magnetic anisotropy; Magnetic properties and materials; Magnetic properties of monolayers and thin films; Magnetic properties of surface, thin films and multilayers; Magnetically ordered materials: other intrinsic properties; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Molecular, atomic, ion, and chemical beam epitaxy; Permalloy; Physics; Step induced magnetic anisotropy
• ISSN: 0304-8853
• DOI: 10.1016/S0304-8853(01)00516-9

The response of magnetization to magnetic field was studied in permalloy film on Mo(0 0 1) stepped surface grown by molecular beam expitaxy on HCP sapphire substrate ( 1 1 ̄ 0 2 ). The magnetization curves exhibit distinctive features as the magnetic field was applied either parallel or perpendicular to the step edges. For field applying parallel to the step edges, the magnetic hysteresis shows a rectangular loop typical of the easy magnetization. Whereas the field applying perpendicular to the step edges, the hysteresis loop displays a complicated feature composed of two split loops. In addition, the variation of the coercivity in function of rotation angles shows that the uniaxial anisotropy axis coincides with one of the cubic anisotropy easy magnetization axis. In addition, from the magnetization curve, the effective four-fold and uniaxial anisotropy constants are determined. Underlying mechanisms associated to the strain-induced anisotropy are discussed.