Anomalous Hall effect and perpendicular magnetic anisotropy in Sm28Fe72 and Sm32Fe68 thin films

Sm28Fe72 and Sm32Fe68 films of 100 nm thickness were grown using DC magnetron sputter deposition and their structure, magnetization, electrical and Hall resistance characteristics were investigated. An increase in electrical resistivity from 4.75 x 10(-6) to 5.62 x 10(-6) Omega m and from 2.26 x 10(-6) to 2.84 x 10(-6) Omega m for Sm28Fe72 and Sm32Fe68 films, respectively, with decrease in temperature from 300 to 40 K is attributed to the strain induced anisotropy that dominates at lower temperatures. The positive extraordinary Hall coefficients (R-S) are observed for both films at 300 and 80 K. The existence of hysteresis indicates that Sm28Fe72 and Sm32Fe68 films possess perpendicular anisotropy at 300 K. Hysteresis loop becomes narrow at 80 K for both Sm28Fe72 and Sm32Fe68 films. Magnetization measurements at 300 K exhibiting small coercive field values of 31 and 49 Oe for Sm28Fe72 and Sm32Fe68 films, respectively, confirm the existence of perpendicular anisotropy at 300 K. (C) 2010 Elsevier B. V. All rights reserved.