Title :
Thermomagnetic recording behavior in the NdTbDyFeCo/DyFeCo-ultrathin bilayer
Author :
Kawase, T. ; Ishida, M. ; Hoshina, S. ; Takakuwa, A. ; Nebashi, S. ; Shimoda, T.
Author_Institution :
Seiko Epson Corp., Nagano, Japan
fDate :
11/1/1994 12:00:00 AM
Abstract :
Thermomagnetic recording behavior was investigated in a bilayer which was composed of a TM-rich NdTbDyFeCo layer and a high-Tc RE-rich DyFeCo ultrathin layer. The magnetic field sensitivity of the bilayer was investigated by a magnetic field modulation method at a low field of 4 kA/m. Carrier-to-noise-ratio depends sensitively on the thickness of the ultrathin layer and reaches its maximum value at approximately 2.5 nm. Using a polarized light microscope it was observed that the domain formation process makes a transition from nucleation-dominated (ND) to wall-motion-dominated (WMD) as the thickness increases, and during the transition the highest magnetic field sensitivity was achieved. We explained those results with a model in which the domain formation started in WMD and ended in ND
Keywords :
cobalt alloys; demagnetisation; dysprosium alloys; ferromagnetic materials; iron alloys; magnetic domain walls; magnetic domains; magnetic multilayers; neodymium alloys; nucleation; terbium alloys; thermomagnetic recording; 2.5 nm; NdTbDyFeCo-DyFeCo; NdTbDyFeCo/DyFeCo-ultrathin bilayer; carrier-to-noise-ratio; domain formation process; magnetic field modulation method; magnetic field sensitivity; nucleation-dominated process; polarized light microscope; thermomagnetic recording behavior; wall-motion-dominated process; Magnetic fields; Magnetic films; Magnetic force microscopy; Magnetic modulators; Magnetic recording; Magnetization; Neodymium; Optical polarization; Sputtering; Temperature dependence;
Journal_Title :
Magnetics, IEEE Transactions on
