Experimental and DFT study of Ni–MgO nanocomposite for magnetic hyperthermia

This study reports a combined experimental and theoretical investigation of nanocrystalline (100−x)Ni/(x)MgO nanocomposite (x = 20, 30, 40 wt%) prepared via mechanical alloying for magnetic hyperthermia applications. Structural analysis using X-ray diffraction revealed successful formation of Ni–MgO nanocomposites with progressive lattice expansion and reduced crystallite size due to Mg incorporation and mechanical strain. Magnetic measurements showed a clear decrease in saturation magnetization (Ms) and an increase in coercivity (Hc) with increasing Mg content. Heating performance under an alternating magnetic field exhibited a composition-dependent behavior, with 30% of MgO achieving the highest specific absorption rate (∼26 W/g), indicating an optimal balance of magnetic properties for thermal conversion. Complementary density functional theory calculations confirmed the observed trends, showing reduced magnetic moments, increased internal lattice distortion, and suppressed Ni 3d density of states at the Fermi level with higher Mg substitution. The strong agreement between experimental data and theoretical calculation indicates the effectiveness of MgO in tailoring the structural, magnetic, and magnetothermal properties of Ni-based nanomaterials, advancing their application potential in self-regulating magnetic hyperthermia.