Er3+ ion-doped Mg-Zn nanoferrite: Properties and applications in dielectric, magnetic, structural, and optical domains affected by calcination temperature

Abstract

A series of Mg-Zn ferrites with Er3+ion doping in the shape of cubic spinel were produced using the citrate sol–gel auto-combustion process known as Mg0.5Zn0.5Er0.1Fe1.9O4 (MZE) (calculated at 400, 550, 700, 850, and 1000 °C), and the same was confirmed with the XRD diffractograms. It was possible to understand the presence of hydrated water, which degrades behavior. Hence, the powders created were sintered at various temperatures for four hours. After that, it was observed that the cubic spinel phase was free of impurities. The as-prepared spinel Mg-Zn ferrite nanoparticles also showed a specified behaviour, according to the results. The SEM, UV–Vis spectroscopy, FT-IR (Fourier transform infrared) spectroscopy, TG-DTA (thermogravimetric and differential thermal analysis), XRD (X-ray diffractometer), LCR metre, and VSM (vibrating sample magnetometer) were the characterization techniques used to examine the samples' structural, optical, dielectric, and magnetic properties. A microstructure investigation was done using FESEM analysis. Based on these FESEM measurements, the nanoparticles' sphere-shaped structure was confirmed. FT-IR spectroscopy has been employed to examine the chemical bonds in the spinel ferrite. There is evidence of a shift in bands ν1 and ν2. The produced materials' semiconducting qualities are demonstrated by the optical band gap energy, which is in the range of 1.648–1.798 eV. Variation of dielectric parameters with Er doping was measured in the frequency range from 100 Hz to 1 MHz at room temperature (RT) and at temperatures of 100–400 °C. These results were very well supported by Maxwell-Wagner interfacial polarization. The dielectric properties were observed to decrease with an increase in frequency due to calcinated MZE samples. The magnetic properties of ferrite nanoparticles were investigated in detail at 300 K and 5 K. Early signs of superparamagnetic behaviour have been observed in the prepared sample. It is used in industries like nanoelectronic devices, detectors, imaging devices, super-paramagnetic coils, and magnets.