Non-equilibrium behavior of the magnetization in the helimagnetic phases of the rare earth alloys R_{1-x}Y_{x} (R = Gd, Tb, Dy)

TL;DR

This study investigates the non-equilibrium magnetic behaviors in helimagnetic phases of rare-earth alloys, revealing common features and unique dynamics near transition temperatures, including potential glassy states.

Contribution

It provides new insights into the non-equilibrium phenomena and slow spin dynamics in helimagnetic rare-earth alloys, highlighting possible helical-glass states.

Findings

Observation of ZFC-FC magnetization differences and hysteresis in helimagnetic phases

Detection of strong non-linearity and slow dynamics near the Néel temperature in Gd-based alloy

Evidence suggesting a helical-glass state in Gd_{0.62}Y_{0.38}

Abstract

We have performed DC and AC magnetization measurements for the rare-earth magnetic alloy systems Gd_{0.62}Y_{0.38}, Tb_{0.86}Y_{0.14}, and Dy_{0.97}Y_{0.03}. These materials commonly exhibit a proper helical magnetic structure, and ferromagnetic structure at lower temperatures.In all of these materials, a difference between zero-field-cooled (ZFC) magnetization and field-cooled (FC) magnetization and a hysteresis loop in the M-H curve have been observed in the helimagnetic phases. The non-equilibrium behavior is possibly caused by a common nature, e. g., chiral domain structures. In addition to the above behavior, strong non-linearity of the magnetization and slow spin dynamics have been observed around the N'eel temperature only in Gd$_{0.62}$Y$_{0.38}$. The spin-glass like behavior observed in Gd_{0.62}Y_{0.38} could be related to a novel glassy state such as a helical-glass state.