Title :
Co-Cr films with perpendicular magnetic anisotropy
Author :
Coughlin, Thomas M. ; Judy, Jack H. ; Wuori, Edward R.
Author_Institution :
Central Research Laboratory, St. Paul, Mn
fDate :
11/1/1981 12:00:00 AM
Abstract :
The magnetic properties of RF sputtered Co-Cr films have been studied over a range of preparation conditions extending previous work. Reproducible well-developed perpendicular anisotropy, as would be required for perpendicular recording, was found when the deposition conditions were maintained at an optimum of 170°C substrate temperature, 1.5 KV RF voltage and 5 microns argon pressure. Film thickness was nominally 1 micron. The optimum deposition rate in our system was 120 angstroms/minute due to the differential sputtering rates of Co and Cr. The resulting films had coercivities up to 1500 oersteds and (00.2) hcp X-ray peak width ΔΘ50of 5 degrees, with secondary X-ray peaks observed as well. Columnar growth was observed with grains less than 800 angstrom diameter. A sublayer of poor orientation was observed. Magnetic moment was observed to be about 35% higher than that reported by Iwasaki. Initial background pressure less than 6 × 10-7torr was essential for formation of well-oriented films. The presence of nitrogen caused the appearance of the fcc phase and the loss of perpendicular coercivity. Loss of coercivity also occurred when film composition was nonuniform.
Keywords :
Magnetic anisotropy; Magnetic films; Anisotropic magnetoresistance; Coercive force; Magnetic films; Magnetic properties; Perpendicular magnetic anisotropy; Perpendicular magnetic recording; Radio frequency; Substrates; Temperature; Voltage;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.1981.1061738