Title :
Oxygen effect on the microstructure and magnetic properties of binary CoPt thin films for perpendicular recording
Author :
Hikosaka, Takashi ; Komai, Tomoko ; Tanaka, Yoichro
Author_Institution :
Inf. & Commun. Syst. Lab., Toshiba Corp., Kawasaki, Japan
fDate :
11/1/1994 12:00:00 AM
Abstract :
This paper presents the effect of oxygen on the microstructure of Co-18 at.% Pt perpendicular medium. Oxygen addition to the CoPt films during high Ar pressure (4 Pa) sputtering successfully increased the perpendicular coercivity. 188 kA/m coercivity and 1.2 tesla (T) saturation magnetization were obtained. The perpendicular anisotropy energy was at least 570 kJ/m3. AEM and EDX measurements revealed that the film was composed of crystal grains and amorphous boundaries and that oxygen segregated clearly inside the amorphous boundaries. A TEM image showed a 10 nm grain diameter independent of the oxygen partial pressure. For CoPt films deposited under a lower Ar pressure (2 Pa), oxygen has been found to exist uniformly within the grains and boundaries and showed no significant effect on coercivity
Keywords :
X-ray chemical analysis; cobalt alloys; coercive force; electron microscopy; ferromagnetic materials; grain boundary diffusion; grain boundary segregation; magnetic thin films; perpendicular magnetic anisotropy; perpendicular magnetic recording; platinum alloys; sputtered coatings; 1.2 T; 10 nm; 4 Pa; AEM measurements; CoPt; CoPt thin films; EDX measurements; TEM; amorphous boundaries; crystal grains; magnetic properties; microstructure; oxygen addition; perpendicular anisotropy energy; perpendicular coercivity; perpendicular recording; saturation magnetization; segregation; sputtering; Amorphous materials; Anisotropic magnetoresistance; Argon; Coercive force; Magnetic films; Magnetic properties; Microstructure; Oxygen; Saturation magnetization; Sputtering;
Journal_Title :
Magnetics, IEEE Transactions on
