Title :
Measurements of crystalline anisotropy on longitudinal media
Author :
Chang, Jack J.K. ; Peng, Qingzhi ; Bertram, H. Neal ; Sinclair, Robert
Author_Institution :
Dept. of Mater. Sci. & Eng., Stanford Univ., CA, USA
fDate :
9/1/1996 12:00:00 AM
Abstract :
The crystalline anisotropy constant in both thin film and particulate recording media has been determined utilizing high field torque measurements and transmission electron microscopy (TEM). Extrapolation of torque measurements at 45° to the film plane yields a “infinite field torque” that depends solely on the anisotropy constant, the distribution of easy axes, and the saturation magnetization. The distribution of easy axes was determined by TEM measurements. Using this technique the crystalline anisotropy constant of a CoCrTa thin film disk (M8=690 emu/cc) was found to be 2.2×106 erg/cc. A floppy disk with Co-γFe2 O3 particles (M8=120 emu/cc) yielded crystalline anisotropy constant of approximately 6.0×105 erg/cc
Keywords :
magnetic anisotropy; magnetic particles; magnetic recording; magnetic thin films; magnetic variables measurement; torque measurement; transmission electron microscopy; Co-γFe2O3 particles; Co-Fe2O3; CoCrTa; CoCrTa thin film disk; crystalline anisotropy constant; easy axis; floppy disk; high field torque measurement; longitudinal recording media; saturation magnetization; transmission electron microscopy; Anisotropic magnetoresistance; Crystallization; Magnetic analysis; Magnetic anisotropy; Magnetic field measurement; Magnetic films; Magnetic recording; Perpendicular magnetic anisotropy; Saturation magnetization; Torque measurement;
Journal_Title :
Magnetics, IEEE Transactions on
