Investigation of anomalous spin cluster glass state of a novel Heusler alloy CoRuCrSi using Muon Spin Relaxation (μSR) technique

Imperfections in materials often give rise to unconventional magnetic phases that deviate from standard magnetic ordering, necessitating detailed microscopic investigation through local probes such as Muon Spin Relaxation (μSR). The μSR technique is a well-established and highly sensitive tool for probing intricate magnetic states, including frustrated magnetism and magnetic glassy phases etc. In this proposal, we request μSR measurements on the equiatomic quaternary Heusler alloy CoRuCrSi to delve into its intriguing magnetic characteristics. It is a potential spin cluster glass system, with a freezing temperature around 50 K. At low fields, the clusters freeze into a rare state of negative magnetization, alongside an additional magnetic transition near 15 K. As the field increases, the system undergoes a transformation from this state to a ferrimagnetic phase at around 90 K, before ultimately reaching a fully paramagnetic state. Zero-field μSR (ZF-μSR) will allow us to accurately elucidate the glassy nature of the system and provide microscopic insight into the negative magnetization state, which only exists in weak fields. Longitudinal-field μSR (LF-μSR) will further distinguish between static and dynamic internal fields, a critical step in unravelling the complex magnetic structure. This comprehensive microscopic investigation will enhance our understanding of the system’s intricate and unconventional magnetic configurations.