Modifying the Soft Magnetic Properties of Mn-Zn Ferrites by Ce2O3-Doping and Sintering Temperature Optimization

Abstract

Abundant rare earth-based Ce 2 O 3 was employed as the doping for improving the magnetic performance of low-cost Mn-Zn ferrites. To achieve the best doping effect, the influence of sintering temperature on the microstructure and magnetic properties was also investigated. Based on the characterization of the samples prepared at different sintering temperatures (1250-1350°C) and with various Ce 2 O 3 contents (0-0.05 wt.%), it has been found that the magnetic properties are determined by the grain size, the distribution of the pores, and the internal stress associated with impurities. The amplitude permeability for the samples with small grains shows good frequency stability in the range of 10-100 kHz. Increasing the sintering temperature or doping a certain amount of Ce 2 O 3 can increase the amplitude permeability and reduce the magnetic loss of the ferrite. However, excessive Ce addition or excessive sintering temperature led to increasing magnetic loss. For the sample doped with 0.01 wt.% Ce 2 O 3 , the maximum amplitude permeabilities of 4105 (20 kHz and 100 mT) and 2830 (100 kHz, 100 mT) can be obtained when sintered at 1350°C, while the minimum power loss with 5.4 W/kg (20 kHz, 100 mT) and 46 W/kg (100 kHz, 100 mT) can be achieved at a sintering temperature of 1280°C. The present results indicate that Ce doping cannot only effectively increase the amplitude permeability and decrease the magnetic loss but can also reduce the sintering temperature. The produced ferrites show great potential for the applications in induction heating systems and other fields.

Features of Electron Beam Processing of Mn-Zn Ferrites in the Fore-Vacuum Pressure Range in Continuous and Pulse Modes

“…The most widespread methods of ferrite synthesis include sol-gel [19][20][21][22], traditional ceramic fabrication [23,24], solid-phase reaction [25,26], self-combustion [27,28], laser deposition [29][30][31], radiation-thermal sintering [32][33][34], and others. Ferrite synthesis techniques are continually improving through the introduction of new additives [35], optimization of sintering temperature regimes [36][37][38], and the combination of soft and hard magnetic ferrites [39].…”

TG, DSC, XRD, and SEM studies of the substituted lithium ferrite formation from milled Sm2O3/Fe2O3/Li2CO3 precursors

“…Thus, doping of spinel ferrites with rare earth ions can improve their electrical and magnetic properties. In particular, such changes in the properties of ferrites occur when they are doped with gadolinium (Gd) [33][34][35][36][37][38][39], dysprosium (Dy) [37,[40][41][42][43], neodymium (Nd) [38,[44][45][46], samarium (Sm) [33,[47][48][49][50][51], lanthanum (La) [45,[52][53][54], terbium (Tb) [37,40,[55][56][57], cerium (Ce) [33,37,58,59], thulium (Tm) 1 3 [60], erbium (Er) [37,45,47,61,62], holmium (Ho) [55,63], ytterbium (Yb) [37], and praseodymium (Pr) [55].…”