Unusual Field Dependence of Anomalous Hall Effect in Ta/TbFeCo

TL;DR

This study investigates the anomalous Hall effect in Ta/TbFeCo thin films, revealing unusual triple hysteresis behavior near the compensation temperature due to spin-reorientation phase transitions influenced by magnetic anisotropy.

Contribution

It provides experimental magnetic phase diagrams and theoretical analysis explaining the anomalous hysteresis loops near the compensation point.

Findings

Triple hysteresis loops observed below the compensation temperature.

Magnetic phase diagram reveals spin-reorientation transitions.

Anomalous behavior linked to FeCo sublattice anisotropy.

Abstract

Experimental studies of anomalous Hall effect are performed for thin filmed Ta/TbFeCo in a wide range of temperatures and magnetic fields up to 3 T. While far from the compensation temperature (TM=277 K) the field dependence has a conventional shape of a single hysteresis loop, just below the compensation point the dependence is anomalous having the shape of a triple hysteresis. To understand this behavior, we experimentally reveal the magnetic phase diagram and theoretically analyze it in terms of spin-reorientation phase transitions. We show that one should expect anomalous hysteresis loops below the compensation point if in the vicinity of it the magnetic anisotropy is dominated by FeCo sublattice due to interaction with Ta.