Observation of magnetization reversal processes in Co-Cr and Co-Cr-Ta ultrathin films under the canted magnetic field using anomalous Hall effect

Normalized magnetization vector M-e of ultrathin Co-Cr-Ta films under the c anted magnetic field were derived from the results of anomalous Hall voltag e and the magnetization measured by a vibrating sample magnetometer. The fi lm deposited at high substrate temperature revealed a relatively large amou nt of an in-plane component because of the faint c-axis orientation in the perpendicular direction of the Co-Cr-Ta crystallites. The in-plane componen t at the remanent state seems to be larger for the film with worse c-axis o rientation. The Pt underlayer was normalized to promote c-axis orientation in Co-Cr-Ta films deposited on it at a high substrate temperature above 200 degrees C. A 30 nm-thick Co77Cr20Ta3 film deposited on a 20-nm-thick Pt un derlayer exhibited large perpendicular coercivity. The locus of normalized magnetization of the Co77Cr20Ta3(30 nm)/Pt(20 nm) implied that the film rev ealed a large perpendicular magnetization component even though the magneti c field was applied in the direction out of the normal line. (C) 2000 Ameri can Institute of Physics. [S0021-8979(00)95408-2].