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Article History

Received: 2 November 2025

Accepted: 9 February 2026

First Online: 23 March 2026

Declarations

: The writers report no institutional associations or participations related to this study or body that possesses a monetary stake (such as fees, academic funding, engagement in advisory panels, jobs, advisory services, equity holdings, or rights-licensing deals) or a non-monetary stake (such as individual or occupational connections, memberships, expertise, or convictions) connected to the topic or substances of this research.

: To the best of our knowledge, no study has reported that Holmium-doped Ni–Co ferrites present a unique materials system where the large magnetic moment and strong spin–orbit coupling of Ho 3 ⁺ ions synergistically modify the structural, and magnetic properties of the spinel lattice. Unlike conventional Ni–Co ferrites or other rare-earth substitutions, Ho 3 ⁺ incorporation induces significant lattice distortion, enhances magneto crystalline anisotropy, and suppresses electron hopping conduction, thereby enabling simultaneous tuning of coercivity and resistivity. This distinctive combination of high magnetic performance with improved electrical resistivity makes Ho-doped Ni–Co ferrites particularly novel for high-frequency, microwave, and multifunctional device applications.