Enhanced magnetic and cytotoxic properties of Co-substituted ZnNdFeO₄ spinel ferrites

Abstract This study delves into the magnetic properties and structural features of cobalt-doped ZnNd 0.05 Fe 1.95 O 4 ferrites alongside their cytotoxic effects on HepG2 cancer cells. Nanocrystalline samples with varying Co concentrations (x = 0.00, 0.15, 0.25, 0.35, 0.45, 0.55) were fabricated through sol–gel auto-combustion methodology. Structural analysis via X-ray diffraction demonstrated cubic spinel formation, with a secondary NdFeO 3 phase emerging at higher Co concentrations. Magnetic measurements revealed ferrimagnetic behavior, with saturation magnetization (Ms) escalating from 3.18 emu g −1 to 69.98 emu g −1 as Co content increased. Coercivity (Hc) also rose from 31.25 Oe to 121.3 Oe. The observed enhancement in magnetic parameters with increasing cobalt concentration suggests enhanced magnetic properties, making these materials suitable for high-frequency applications. Cytotoxicity evaluation through MTT protocols revealed notable antiproliferative effects, with optimal results observed at x = 0.45 and 0.55, yielding IC 50 values of 0.97 μg ml −1 , and 4.78 μg ml −1 , respectively, with normal cytotoxicity of Zn 0.55 Co 0.45 Nd 0.05 Fe 1.95 O 4 against normal liver cells. The capacity to modulate these ferrites’ characteristics through systematic cobalt incorporation opens up new avenues for their use in biomedical fields, particularly in cancer treatment, where targeted drug delivery and enhanced imaging capabilities are crucial.