Domain-Wall Pinning in Er and Dy Studied by Minor-Loop Scaling Laws

Abstract

Scaling laws of magnetic minor hysteresis loops for heavy rare-earth metals Er and Dy were studied. We found that there exists a scaling power law between hysteresis loss and remanence of minor loops with a constant exponent of 1.2–1.3 in the low-temperature ferromagnetic phase below Tc as was commonly observed in soft ferromagnetic materials. However, the scaling law persists even in the higher temperature incommensurate antiferromagnetic phase with no net spontaneous magnetization. These observations reflect the irreversible movement of Bloch walls, which separate ferromagnetic domains below Tc or small ferromagnetic regions in the antiferromagnetic phase.