In situ annealing optimization by anomalous Hall effect for a high-entropy alloy

Abstract

An in situ methodology was devised to refine the annealing parameters for a soft magnetic high-entropy alloy, Al0.7NiCoFe1.5Cr1.5. Anomalous Hall measurements were employed to elucidate the magnetic characteristics in real time during annealing. This approach facilitates the determination of an optimal annealing temperature range, centered approximately at 500 °C, within a single annealing process. After annealing, a notable 51.5% enhancement in the saturation magnetization was observed, accompanied by a significant 80.5% reduction in coercivity. Moreover, the methodology enables the acquisition of intricate insights into phase transitions occurring throughout the annealing process. The findings affirm the efficacy of the in situ technique for refining the annealing parameters and underscore its potential applicability in the exploration of microstructural and phase transformations in materials.