Ultra-Soft Ferrimagnetism in a High-Entropy Spinel Oxide Driven by Site-Selective Cation Disorder

Neha Sharma; AmritPal; Nikita Sharma; Mathieu Duttine; Denis Pelloquin; S. D. Kaushik; Sanjoy Mahatha; Olivier Toulemonde; Sourav Marik

arXiv · 2606.10715

Ultra-Soft Ferrimagnetism in a High-Entropy Spinel Oxide Driven by Site-Selective Cation Disorder

Neha Sharma·AmritPal·Nikita Sharma·Mathieu Duttine·Denis Pelloquin·S. D. Kaushik·Sanjoy Mahatha·Olivier Toulemonde·Sourav Marik

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Abstract

High-entropy materials are complex, multifunctional materials that have reshaped the design of advanced functional materials. Their chemically diverse compositions enable access to a broader compositional space than conventional solid solutions, while simultaneously posing significant challenges for fundamental structure property understanding. In this study, we introduce a new highentropy spinel oxide with an exceptionally low coercivity of 1.8 Oe at room temperature, among the lowest reported for bulk spinel oxides, and a high electrical resistivity (1560 ohm-cm). Neutron powder diffraction (NPD) and magnetic measurements reveal long-range collinear ferrimagnetic ordering (k = 0,0,0) with a transition temperature at 420 K. This rare combination of ultra-soft magnetic behavior, robust ferrimagnetic ordering well above room temperature, and high resistivity highlights its strong potential as an advanced soft-magnetic oxide for low-loss, high-frequency applications. Furthermore, X-ray absorption spectroscopy (XAS), Mossbauer spectroscopy, and NPD analyses were combined to determine the cation distribution and site selectivity across the tetrahedral and octahedral sites of the complex structure.

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Neha Sharma, AmritPal, Nikita Sharma, Mathieu Duttine, Denis Pelloquin, S. D. Kaushik, Sanjoy Mahatha, Olivier Toulemonde, Sourav Marik. 2026-06-09. Ultra-Soft Ferrimagnetism in a High-Entropy Spinel Oxide Driven by Site-Selective Cation Disorder. https://arxiv.org/abs/2606.10715

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