Impression of partial replacement of Fe3+ by Sn4+ ion on structural and magnetic features of NiCuZn nanospinel ferrites

Abstract

In the current study, Ni<inf>0.4</inf>Cu<inf>0.2</inf>Zn<inf>0.4</inf>Fe<inf>2?4x</inf>Sn<inf>3x</inf>O<inf>4</inf> (Sn ? NiCuZn) (x ? 0.10) nanospinel ferrites (NSFs) have been fabricated by a citrate sol–gel approach, and their structure, morphology, and magnetic features were investigated via XRD, SEM with EDX, HR-TEM, TEM, and VSM, respectively. Their cubic spinel phase was endorsed from their Rietveld refinement. The products’ D<inf>XRD</inf> (crystallite sizes) were estimated within the 36–69 nm range. The 10 and 300 K magnetization measurements show ferromagnetic and superparamagnetic behaviors, respectively. The saturation magnetization (M<inf>s</inf>) decreases at both temperatures with increasing Sn ratio up to x = 0.06 into the lattice of NSFs but thereafter rises with the additional rise of Sn ratio from 0.06 to 0.10. The alterations of M<inf>s</inf> values with Sn substitution have been deliberated via cation redistribution, and changes in the anisotropy constant. H<inf>c</inf> value at 10 K almost initially increased for lower Sn content and then decreased at higher Sn content. The coercivity is in reverse proportionality to the particle/crystallite size and domain wall movement of ferromagnetism. © 2025 Elsevier B.V., All rights reserved.