FMR experiment in multilayer structure of FeBSi/Pd

• Published in: Journal of magnetism and magnetic materials 1992-03, Vol.109 (2), p.341-348
• Main Authors: Maksymowicz, L.J., Jankowski, H.
• Format: Article
• Language: English
• Subjects: Applied sciences; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Magnetic properties and materials; Magnetic properties of surface, thin films and multilayers; Metals. Metallurgy; Physics
• ISSN: 0304-8853
• DOI: 10.1016/0304-8853(92)91771-K

The surface anisotropy energy and coupling interaction of the multilayered structure of metallic glasses of FeBSi/Pd were investigated, rf-sputtered thin films were studied by means of an X-band microwave spectrometer. The surface mode excitations in a spin wave resonance (SWR) experiment were used to derive the surface anisotropy energy constant K s, applying the surface inhomogeneity (SI) model with the symmetrical boundary conditions. The energy of surface anisotropy was given as K s = − K s cos 2 θ, whsre θ was the angle between the magnetization and the film normal. The surface anisotropy energy constant K s was assumed to be the superposition of two terms K s 1 and K s 2. The origin of the second term K s 2 was considered to be from the magnetic polarization of interfacial Pd atoms; hence the depth of interdiffusion of Pd into metallic glass was also calculated. The first term K s 1 could be treated as originating from other effects which alter the surface spins at the interfaces such as misfit strain anisotropy, surface roughness and Néel's anisotropy. The value of K s 1 was evaluated from the surface mode excitation data of single metallic glasses films of Pd/FeBSi/Pd with small values of M s, so the effects of induced ferromagnetism on the Pd interfacial atoms could be neglected. The coupling interaction effective field H eff was determined from the ferromagnetic resonance (FMR) data in a rotating external magnetic field. For the fixed thickness d of the magnetic sublayer the thickness t of Pd varied from 3.5 to 18.0 nm. Only coupling effects were investigated. We did not expect the exchange interaction through an intervening nonmagnetic layer with t > 2.0 nm. It was found that even for t = 18.0 nm the coupling interaction still existed. It is getting to be less affected by the value of t and we assumed it to be probably due to the stresses.