Title :
Structure and Isotropic High-Frequency Response of Co-HfN Nanogranular Films
Author :
Yang Cao ; Yiwen Zhang ; Ohnuma, Shigehiro ; Kobayashi, Nobukiyo ; Masumoto, Hiroshi
Author_Institution :
Frontier Res. Inst. for Interdiscipl. Sci., Tohoku Univ., Sendai, Japan
Abstract :
The Co-HfN nanogranular films with different Co content were deposited, to obtain high-frequency soft magnetic properties. The films exhibit perpendicular magnetic anisotropy over a wide composition range. The coercivity is ~15-75 Oe, which is attributed to the growth-induced Co columnar structure. Both hysteresis loops and magnetic force microscopy images demonstrate that the films are magnetically in-plane isotropic. The permeability and ferromagnetic resonance frequency of the Co58Hf14N28 films are 40 and 2 GHz, respectively, which is consistent with the theoretical calculation based on Landau-Lifshitz-Gilbert (L.L.G) equation. The films consist of crystallized Co nanogranules and amorphous HfN matrix.
Keywords :
amorphous state; cobalt; coercive force; ferromagnetic resonance; hafnium compounds; magnetic force microscopy; magnetic hysteresis; magnetic permeability; magnetic thin films; nanofabrication; nanomagnetics; nanostructured materials; nitrogen; perpendicular magnetic anisotropy; soft magnetic materials; Co-HfN nanogranular films; Co58Hf14N28; Landau-Lifshitz-Gilbert equation; amorphous HfN matrix; coercivity; crystallized Co nanogranules; ferromagnetic resonance frequency; growth-induced Co columnar structure; high-frequency soft magnetic properties; hysteresis loops; isotropic high-frequency response; magnetic force microscopy; magnetic permeability; perpendicular magnetic anisotropy; structure response; Films; Magnetic hysteresis; Magnetic noise; Magnetic properties; Perpendicular magnetic anisotropy; Soft magnetic materials; Cobalt alloys; frequency response; perpendicular magnetic ansotropy; soft magnetic materials;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2015.2438003
