Coexistence of Ferromagnetic and a Re-entrant Cluster Glass State in the Layered Quaternary (Cr1−x,Mnx)2GeC

Herein we present evidence for the coexistence of a Mn-rich ferromagnetic (FM) state and a Mn-poor reentrant cluster glass state in bulk, polycrystalline, layered (Cr1−x,Mnx)2GeC samples, where x is varied between 0.01 and 0.1. The Mn-poor regions form a reentrant cluster glass state below ∼30 K. The Mn-rich regions become FM at Curie temperatures that increase with increasing Mn content. The interface coupling between these two regions gives rise to exchange anisotropy and a change in sign at 20 K resulting in, rarely observed, inverted hysteresis loops.