Evidence of a magnetic glass state in the magnetocaloric materialGd5Ge4

Abstract

We demonstrate the kinetic arrest of the first-order phase transition from the high-temperature antiferromagnetic state to the ferromagnetic ground state in zero and low applied magnetic fields, occurring within the experimental time scale in the magnetocaloric material ${\mathrm{Gd}}_5{\mathrm{Ge}}_4$. A magnetization study clearly reveals glasslike dynamics in the low-temperature antiferromagnetically ordered state. The observation of a glasslike magnetic state is unusual, but we expect that a similar phenomenon should exist in other magnetic systems.