Influence of La3+ ions doping on morphology and magnetic properties of Mg–Co ferrites

In this study, magnesium–cobalt nanoferrites (MCNF) doped with La3+ ions were prepared by sol–gel method. The chemical formula of the samples prepared was Mg0.2Co0.8Fe2-xLaxO4 (x = 0.0, x = 0.025, x = 0.05, x = 0.075, x = 0.1). The crystal structure of the samples and the successful doping of La3+ ions can be obtained by X-ray diffraction (XRD). Fourier transform infrared spectroscopy (FTIR) reflects the information of absorption bands and functional groups in a certain range. According to the position of different absorption bands, it can be judged that the chemical reaction has been completed in the preparation process. Scanning electron microscopy (SEM) images showed that the sample is spherical, the particle size distribution is narrow, and the sample size is uniform. Energy dispersion spectroscopy (EDS) was used to characterize the specific elements in the samples and confirmed that the elements in the samples were Mg, Co, Fe, La, and O. There were no other impurities in the samples. Vibrating sample magnetometer (VSM) is used primarily to analyze the magnetic properties of samples. The results demonstrate that the doping of La3+ ions can change the crystal properties of the samples, and Mg0.2Co0.8Fe2-xLaxO4 has a cubic spinel structure. The coercivity of the sample is between 611.24 and 779.43 Oe, and it has the properties of hard magnetic materials.