Effect of MoO3 Doping on the Microstructure and Magnetic Properties of Mn0.816Zn0.091Fe2.093MoxO4

The traditional solid-state method was employed in this study to prepare Mn-Zn ferrite. By adjusting the sintering temperature and the MoO3 doping ratio, the evolution of its structural and magnetic properties was systematically investigated. Fe2O3, MnO, and ZnO were used as the main raw materials, with MoO3 serving as an additive. MoO3 was doped at molar ratios ranging from 0 to 1000 ppm under experimental conditions involving a sintering temperature between 1125 °C and 1165 °C and an oxygen concentration of 1.5%. The addition of an appropriate amount of MoO3 led to an increase in the Q value, which consequently resulted in a reduction in the loss. The formation of a single-phase spinel structure was confirmed by X-ray diffraction analysis. Observations of the surface morphology revealed that the grain size also increased with the increase in MoO3 content, a trend consistent with the enhanced grain growth kinetics at higher MoO3 levels. In this study, a Mn-Zn ferrite material with excellent comprehensive performance was successfully prepared under the optimal conditions of a sintering temperature of 1150 °C and a MoO3 doping concentration of 500 ppm. A Q value of 22.3 was obtained for this material at 25 °C, while a Q value of 15.7 was obtained at 100 °C. At room temperature, a Q value of 192.4 was measured at a test frequency of 500 kHz, and a Q value of 137.2 was measured at 1 MHz. At a frequency of 500 kHz, a loss of 27.1 kW/m3 was observed at 25 °C, and a loss of 53.6 kW/m3 was observed at 100 °C. At a frequency of 1 MHz, a loss of 88.2 kW/m3 was recorded at 25 °C, while a loss of 183.7 kW/m3 was recorded at 100 °C. Additionally, the lattice constant was stabilized in the range of 8.52–8.53 Å, indicating favorable structural stability.