Year: 2026
Type: preprint
Abstract: We report the experimental investigation of the quaternary Heusler alloy NiRuMnGa, complemented by first-principles calculations. The energetically favorable crystal structure was identified from first-principles calculations and subsequently used as the structural model for refinement of the powder X-ray diffraction data. The refinement shows good agreement with the experimental pattern and reveals substantial B2-type disorder involving Ni/Ru and Mn/Ga site intermixing. The dc magnetic response exhibits pronounced ZFC--FC irreversibility near $\sim 48$ K, with the irreversibility temperature shifting toward lower temperatures under increasing magnetic field, indicating a field-sensitive glassy state. The isothermal magnetization remains unsaturated up to 7 T, reaching only $\sim 0.4\,μ_{\mathrm{B}}$/f.u., accompanied by pronounced hysteresis, suggesting competing exchange interactions and frustrated magnetic moments. AC susceptibility, together with magnetic relaxation and memory measurements, confirms slow spin dynamics characteristic of a cluster glass state. The lack of a discernible heat-capacity anomaly near the irreversibility temperature further supports the absence of conventional long-range magnetic order. Collectively, these results demonstrate that competition between ferromagnetic and antiferromagnetic interactions in NiRuMnGa leads to magnetic frustration and stabilizes a cluster glass state.
Source: arXiv (Cornell University)
Institutions: National Institute of Technology Andhra Pradesh, Indian Institute of Science Education and Research Berhampur, Centre National de la Recherche Scientifique, École Nationale Supérieure d'Ingénieurs de Caen, Laboratoire de Cristallographie et Sciences des Matériaux, Université de Caen Normandie
Language: English
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
Award: G4234585386
OpenAlex ID: W7221519051