Study of temperature dependence of photoluminescence and raman scattering of (Zn, Al) substituted magnesium spinel ferrite

Background: Substituted Mg nanoferrite attracted attention recently according to their capability for using in high-density magnetic recording applications, biotechnological applications and microwave control components. Objective: This article studied the temperature dependence of photoluminescence and Raman scattering of Zn2+ and Al3+substituted Mg nano spinel ferrites using a 325-and 758-nm He–Cd laser as an excitation source. Methods: Zn2+ and Al3+-substituted Mg nano spinel ferrites were fabricated at different ratios by co-precipitation method, the resulted powder was ground and sintered at 600°C for 10 h. The structure, particle size, and morphology of the spinel ferrites were confirmed with X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Results: The photoluminescence at different temperatures was investigated by studying the energy, intensity, and bandgap. The spectra exhibited a broadband consisting of two bands at 1.8 and 2.2 eV, indicated by their redshift. An Arrhenius model was used to fit the integrated photoluminescence as a function of the inverse temperature to calculate the activation energy. The Raman spectra reasonably fit the spinel ferrite structure of the synthesized nano spinel ferrites. The modes at 798 and 802 cm-1 exhibited a softening with increasing temperature owing to the effect of the substituted ions on the spinel microstructure.