<p>Spinel-structured nanomaterials have become a significant focus of research as a result of their promising biological uses and advanced technological applications. Nickel cobalt ferrite, in particular, stands out for super-capacitor applications. Since synthesis methods influence its structural and magnetic properties, studying temperature dependence on cation distribution of Ni–Co ferrite nanoparticles provides important information about the material’s structural, morphological, and magnetic characteristics of Ni_0.8Co_0.2Fe₂O₄ ferrite. The arrangement of cations in lattice sites depends largely on how the material is prepared. Therefore, analyzing cation distribution and structural details is essential for optimizing material performance. x-Ray powder diffraction analyzed through Rietveld refinement is a trusted method widely used to study cation distribution in crystal lattices. Nevertheless, even with significant research, the precise influence of cation rearrangement on the structure and magnetic characteristics of Ni–Co ferrites remains incompletely clarified. This research employed the sol–gel assisted autocombustion method to synthesize Ni_0.8Co_0.2Fe₂O₄ ferrite nanoparticles, investigating how cation arrangement affects their structural and magnetic behavior. x-Ray diffraction (XRD) analysis confirmed that the calcined nanocrystalline nickel-cobalt ferrite exhibits a spinel-type crystal arrangement with cubic symmetry, having the <InlineEquation ID="IEq1"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="11664_2025_12331_Article_IEq1.gif" Format="GIF" Height="16" Rendition="HTML" Resolution="72" Type="Linedraw" Width="41" /> </InlineMediaObject> <EquationSource Format="TEX">\({\text{Fd}}\overline{3}{\text{m}}\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mtext>Fd</mtext> <mover> <mn>3</mn> <mo>¯</mo> </mover> <mtext>m</mtext> </mrow> </math></EquationSource> </InlineEquation> space group. It is observed that crystallites become larger, increasing from 28.94 to 49.05 with the increasing calcination temperature up to 600°C. The Fourier transform infrared spectroscopy (FTIR) also confirms the existence of the nanocrystalline spinel structure by identifying the characteristics of two metal-oxygen vibrational bands near 350–600 cm⁻¹, associated with A-sites and B-sites in the crystal structure. A vibrating sample magnetometer (VSM) was used to assess the magnetic behavior, which indicates a rise in magnetic saturation from 32.979&#xa0;emu/g to 41.786 emu/g, and coercivity lies between 906.7 Oe and 642.9 Oe with increasing calcination temperature, which demonstrates that saturation magnetization (<InlineEquation ID="IEq2"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="11664_2025_12331_Article_IEq2.gif" Format="GIF" Height="16" Rendition="HTML" Resolution="72" Type="Linedraw" Width="23" /> </InlineMediaObject> <EquationSource Format="TEX">\({M}_{\text{s}}\)</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>M</mi> <mtext>s</mtext> </msub> </math></EquationSource> </InlineEquation>) and coercivity (<InlineEquation ID="IEq3"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="11664_2025_12331_Article_IEq3.gif" Format="GIF" Height="16" Rendition="HTML" Resolution="72" Type="Linedraw" Width="21" /> </InlineMediaObject> <EquationSource Format="TEX">\({H}_{\text{c}}\)</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>H</mi> <mtext>c</mtext> </msub> </math></EquationSource> </InlineEquation>) exhibit significant variations with elevating temperature. The combined structural and magnetic analyses reveal that Ni_0.8Co_0.2Fe₂O₄ spinel ferrite maintains strong thermal stability, positioning it as a potential candidate for advanced magnetic applications (e.g., magnetic resonance imaging (MRI), magnetic storage, hyperthermia, and drug delivery).</p> Graphical Abstract <p></p>