A new nano-grain Mn-Zn spinel ferrite smart cores to enhance the efficiency of high-frequency devices

Mn-Zn ferrites are widely interested in the application as current-compensated chokes due to their astounding features. In this study, nanocrystalline Mn-Zn ferrite (Mn_0.8Zn_0.2Fe₂O₄) was synthesized using the coprecipitation method. The structures and magnetic properties of the resulting powder were assessed using X-ray diffractometer (XRD), transmission electron micrographs (TEM), magnetic properties at room temperature (AGFM) and Curie temperature measurement. XRD pattern confirmed the formation of nanocrystalline Mn-Zn ferrite with average crystallite sizes in 11.3 nm. The magnetic measurements revealed that they have superparamagnetic behavior. The electromagnetic properties of these cores including the output voltage versus input voltage, quality factor and impedance versus frequency at four sintered temperatures were assessed. The results demonstrated that the fabricated smart core sintered at low temperature (800 °C) could efficiently be appropriate for work in a test frequency of 15 MHz. This encouraging feature suggests that it is worthwhile for application in modern switch-mode power supply modules. (author)