Studies of Structural, Optical, and Raman Analysis of Ni‐Substituted CoFe2O4

The polycrystalline ferrite samples of Ni x Co 1− x Fe 2 O 4 ( x = 0.1, 0.3, 0.5, 0.7, and 0.9) are synthesized through the well‐known sol–gel method. The X‐ray diffraction (XRD) pattern confirms the cubic single‐phase spinel structure. Rietveld refinement indicates the absence of any other impurity phases in the samples. Additionally, XRD analysis reveals variations in lattice parameters corresponding to the doping. The Debye Scherer formula has been used to calculate the crystallite size of the samples, the crystallite size of the samples existing in the nanoregime. The results from field emission scanning electron microscopy confirm the morphological structure of the prepared samples. Additionally, the energy‐dispersive X‐ray spectra confirm the elemental composition and purity of the synthesized samples, validating the appropriateness of doping in the polycrystalline samples. The Raman spectra give the information about the vibrational modes in the sample. The Fourier transform infrared rays spectrum shows that the samples have a broad range of chemical interactions. The photoluminescence spectroscopy (PL) suggests strong luminescence in the visible range. PL spectroscopy provides that PL intensity decreases with increasing excitation wavelength due to nanosize of the particle.