Title :
Triple-layer perpendicular recording media for high SN ratio and signal stability
Author :
Ando, Toshio ; Nishihara, Toshikazu
Author_Institution :
Central R&D Center, Victor Co. of Japan Ltd., Yokohama, Japan
fDate :
9/1/1997 12:00:00 AM
Abstract :
Media noise, SN ratio, and signal stability of triple-layer (TL) perpendicular recording media are studied. The TL medium is composed of a CoCrTa perpendicular layer, an amorphous CoZrNb soft magnetic layer, and a CoSm in-plane hard magnetic pinning layer. A high SN ratio is obtained due to the pinning effect of the CoSm layer and with an optimum CoCrTa perpendicular layer of a 50-nm-thick Co-Cr20-Ta3.5at% (Ms=400 emu/cm3) film. High signal stability against stray magnetic fields is obtained in TL media with a 600-nm-thick CoZrNb layer. Moreover, no thermal magnetic relaxations occurs in TL media at 60°C for 5 hours and at room temperature for 15 hours. The TL media are promising as practical ultrahigh-density recording media having high read-write reliability
Keywords :
chromium alloys; cobalt alloys; ferromagnetic materials; magnetic domains; magnetic multilayers; magnetic recording noise; niobium alloys; perpendicular magnetic recording; samarium alloys; tantalum alloys; zirconium alloys; 20 to 60 degC; 5 to 15 h; 50 nm; 600 nm; CoCrTa-CoZrNb-CoSm; SN ratio; in-plane hard magnetic pinning layer; media noise; pinning effect; read-write reliability; signal stability; soft magnetic layer; stray magnetic fields; triple-layer perpendicular recording media; ultrahigh-density recording media; Amorphous magnetic materials; Amorphous materials; Magnetic fields; Magnetic films; Magnetic noise; Perpendicular magnetic recording; Signal to noise ratio; Soft magnetic materials; Stability; Tin;
Journal_Title :
Magnetics, IEEE Transactions on
