Magnetic Relaxation Phenomena in a CuMn Spin Glass

TL;DR

This study investigates the non-equilibrium spin configurations in a CuMn spin glass through temperature and time-dependent magnetization experiments, revealing how cooling rate and halts influence the system's magnetic state.

Contribution

It provides new insights into how spin configurations are imprinted and evolve during cooling, highlighting the effects of cooling rate and temperature halts on magnetization.

Findings

Cooling rate affects the magnitude of FC magnetization.

Halts at constant temperature imprint extended spin configurations.

Relaxation behavior reflects non-equilibrium spin states.

Abstract

Experiments on the temperature and time dependence of the response function and the field cooled magnetisation of a Cu(Mn) spin glass at temperatures below the zero field spin glass temperature are used to explore the non-equilibrium nature of the underlying spin configuration. The results imply that a certain spin configuration is imprinted on the system as the temperature is decreased at a constant cooling rate. The cooling rate governs the magnitude of the FC magnetisation (M_{FC}(H,T)). Any intermittent halt at a constant temperature, T_{i}, imprints an extended spin configuration, a process that is reflected e.g. in a downward relaxation of M_{FC}. On continued cooling at the same rate, the magnitude of M_{FC}(T) remains at a lower level than that of a continuous cooling curve. These results are put into the context of the corresponding behaviour of the response function as observed in measurements of the relaxation of the zero field cooled magnetisation.