Title :
Time-Resolved Kerr Effect in Very Thin Films of CoCrPt Alloys
Author :
Mizukami, S. ; Watanabe, Daisuke ; Kubota, Takahide ; Zhang, Xiaobing ; Naganuma, H. ; Oogane, M. ; Ando, Y. ; Miyazaki, Toshimasa
Author_Institution :
WPI-Adv. Inst. for Mater. Res., Tohoku Univ., Sendai, Japan
Abstract :
Fast precessional dynamics of magnetization are reported in very thin films of CoCrPt alloy with large perpendicular magnetic anisotropy. The films are fabricated with different substrate temperatures, and magnetization dynamics are investigated using time-resolved magneto-optical Kerr effect. The Kittel´s equation well describes a dependency of magnetization precession frequency on an applied magnetic field direction for all the films, only when the field is relatively large. An inverse lifetime of magnetization precession, a counterpart of a line width in ferromagnetic resonance (FMR), depends strongly on the field direction even at the applied field of around 10 kOe. The Gilbert damping constant α is estimated to be ~0.05 for all the films using a model taking account of an influence of perpendicular magnetic anisotropy dispersion.
Keywords :
Kerr magneto-optical effect; chromium alloys; cobalt alloys; damping; ferromagnetic materials; ferromagnetic resonance; magnetic thin films; metallic thin films; perpendicular magnetic anisotropy; platinum alloys; time resolved spectra; CoCrPt; Gilbert damping constant; Kittel equation; fast precessional dynamics; ferromagnetic resonance; large-perpendicular magnetic anisotropy dispersion; magnetization; thin film alloys; time-resolved magneto-optical Kerr effect; Damping; Magnetic resonance; Magnetization; Magnetomechanical effects; Metals; Perpendicular magnetic anisotropy; Magnetic films; magnetic resonance; magneto-optic Kerr effects; perpendicular magnetic anisotropy (PMA);
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2011.2154357