<p>In the present study, (Ni₆₀Co₄₀)₈₅Fe₁₅ nanostructured powders were synthesized by the hydrothermal route. Our study examines the effect of different concentrations of sodium hydroxide (NaOH) on structural, microstructural, and hyperfine properties. The X-ray diffraction results show that all the samples exhibited a face-centered cubic (fcc) structure. As the NaOH concentration increases, a slight increase in lattice parameters and a progressive increase in average grain size were observed. Fourier transform infrared spectroscopy (FTIR) is employed to examine the surfaces of integrated Ni-Co-Fe nanocomposites, allowing for the identification of the principal bands of our ternary system. SEM analysis showed that particle size was strongly influenced by the NaOH concentration, with the particles assuming an almost spherical shape and morphology as the NaOH concentration increases. SEM analysis showed that particle size was strongly influenced by the NaOH concentration, with the particles assuming an almost spherical shape and morphology as the NaOH concentration increases. The Mössbauer spectra analysis performed at room temperature (RT) confirms the XRD results, verifying the formation of the ferromagnetic NiCoFe solid solution and revealing the presence of a new non-ferromagnetic phase.</p>