In this paper, barium ferrite powders were synthesized by sol-gel method, calcined at different temperatures, and on this basis the corresponding ceramics were prepared. The effects of calcination temperature on the structure, magnetic, dielectric and multiferroic properties of BaFe12O19 ceramics were studied. XRD results confirmed similarity between powders and ceramics, where dominant phase is BaFe12O19 and a small amount of an apparent BaFe2O4 impurity phase was formed at lower calcination temperature. The impurity BaFe2O4 phase is the main reason for decreasing powder magnetization. The maximum dielectric constant of 100 (at 10 kHz) and maximum remanent polarization, remanent magnetization and saturation magnetization of 0.46 ?C/cm2, 47.37 emu/g and 79.96 emu/g, respectively, were obtained in the barium ferrite ceramics prepared from the powder calcined at 1100?C. This research could be the basis for the study of single-phase multiferroic materials and the development of multi-order electronic devices.

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Multiferroic materials attracted much attention because of magnetoelectric (ME) coupling effect. Herein, a typical single-phase multiferroic BiFeO3 (BFO) was co-doped at A and B sites by solid-state method, and Bi0.78La0.08Sm0.14Fe0.85Ti0.15O3 (BLSFTO) ceramics were prepared at different sintering temperatures (940, 960, 980 and, 1000?C). The effects of sintering temperature on the microstructure, morphology, dielectric, ferroelectric and magnetic properties were systematically studied. The remanent polarization (Pr) and coercive field (Ec) of the BLSFTO ceramics show a non-linear change with sintering temperature. The remanent polarization reaches maximum (0.0560 ?C/cm2) in the sample sintered at 1000?C, whereas the maximum Ec of 1.32 kV/cm was obtained in the specimen sintered at 940?C. The remanent magnetization (Mr) increases with the increase of sintering temperature, while change of the saturation magnetization with sintering temperature is negligible. When BLSFTO specimen is sintered at 1000?C, Mr reaches the maximal value of 0.1344 emu/g.