Magnetic ground state, evolution, and critical dynamics in the new generation diluted ferromagnetic semiconductors Li(Zn,Mn)As: a μSR perspective

Muon spin rotation/relaxation/resonance (μSR) is uniquely suited to probe the magnetic ground state, phase evolution, and critical spin dynamics central to understanding ferromagnetism in diluted magnetic semiconductors (DMSs). Here, we report a comprehensive μSR study on Li(Zn,Mn)As, a new-generation, bulk, air-stable DMS isostructural to the prototypical DMS system (Ga,Mn)As. Our results yield three key advances: (1) We provide the first quantitative μSR-based map of the paramagnetic-to-ferromagnetic evolution, identifying a percolation threshold of approximately 5% Mn for achieving homogeneous long-range order under a fixed charge carrier doping level. (2) We clarify that the magnetic ground state is purely static in the homogeneous regime but exhibits coexistence of static and dynamic magnetism in the phase-separated state. (3) We demonstrate that near the Curie temperature, the transition in both the homogeneous state and the phase-separated state demonstrates no critical spin dynamics. These results can be partially explained within the framework of bound magnetic polaron models previously used for other DMS systems.