Polarity Reversal of Hall Voltage at Compensation Temperature in Amorphous RE-Ni (RE:Gd, Tb, Dy, Ho) Films with Perpendicular Magnetic Anisotropy

Various amorphous rare earth - Ni (ferrimagnetic) films were prepared, and the temperature dependences of their Hall loops studied, to elucidate the mechanism by which the Hall polarity is suddenly reversed at the compensation temperature Tcomp. The polarity of VH was found to change from positive to negative at Tcomp in all cases, in contrast with RE-Co(Fe) films, which change from negative to positive. At temperatures below Tcomp, where the Gd spin dominates, ¿H ≫ 0, lending support to the hypothesis that the transition metal spin plays a dominant role in the Hall effect mechanism in RE-TM films.