Title :
Control of In-Plane Uniaxial Anisotropy of CoPd-CaF
Nanogranular Films by Tandem-Sputtering Deposition
Author :
Naoe, M. ; Kobayashi, N. ; Ohnuma, S. ; Watanabe, M. ; Iwasa, T. ; Masumoto, H.
Author_Institution :
Res. Inst. for Electromagn. Mater., Sendai, Japan
Abstract :
In-plane uniaxial anisotropic CoPd-CaF2 nanogranular soft magnetic films for gigahertz applications were prepared using RF tandem-sputtering deposition with substrate revolution. Strong anisotropy with a large anisotropy field exceeding 50 kA/m was achieved in the centrifugal-centripetal direction of the substrate revolution, regardless of the presence or absence of an applied external dc field for induced anisotropy. X-ray pole-figure analysis demonstrated that the crystalline orientation of CoPd111 as a crystallographically magnetic easy axis corresponds to the easy axis of the films. Thus, the soft magnetic properties and uniaxial anisotropy of nanogranular films are determined by both random-magnetocrystalline and shape anisotropies. Complex permeabilities indicated high ferromagnetic resonance frequency exceeding 5GHz with a low Gilbert damping factor of 0.06 for the nanogranular films, and the applied field caused a change in the damping factor. Thus, the magnetic properties of the films can be controlled by the substrate motion and the applied field under tandem-sputtering conditions.
Keywords :
calcium compounds; cobalt alloys; crystal orientation; ferromagnetic resonance; granular materials; induced anisotropy (magnetic); magnetic permeability; nanofabrication; nanomagnetics; nanostructured materials; palladium alloys; soft magnetic materials; sputter deposition; texture; CoPd-CaF2; Gilbert damping factor; RF tandem-sputtering deposition; X-ray pole-figure analysis; applied external dc field; centrifugal-centripetal direction; complex permeabilities; crystalline orientation; crystallographically magnetic easy axis; ferromagnetic resonance frequency; gigahertz applications; in-plane uniaxial anisotropic nanogranular soft magnetic films; induced anisotropy; random-magnetocrystalline anisotropy; shape anisotropy; soft magnetic properties; substrate motion; substrate revolution; Anisotropic magnetoresistance; Magnetic films; Magnetomechanical effects; Microwave magnetics; Perpendicular magnetic anisotropy; Soft magnetic materials; Microwave magnetics; Soft magnetic materials; anisotropy dispersion; magnetocrystalline anisotropy; nanogranular films; soft magnetic materials; uniaxial anisotropy;
Journal_Title :
Magnetics Letters, IEEE
DOI :
10.1109/LMAG.2014.2372691