In situ synthesis of multiferroic YMnO3 ceramics by SPS and their characterization

Dense YMnO3 multiferroic ceramics were prepared by a novel technique of in situ SPS (spark plasma sintering) combined with annealing, and both the dielectric and magnetic characterizations were conducted. Compared with the conventional ceramic process, the synthesis process was greatly simplified, and dense YMnO3 ceramics with uniform microstructures were achieved at a relatively low temperature in very short time. Dielectric characteristics of dense YMnO3 ceramics were well evaluated over broad temperature and frequency ranges. An obvious dielectric relaxation was observed in the low temperature range and a dielectric step was detected in the higher temperature range. Systemic magnetism studies of the present YMnO3 ceramics indicated a weak ferromagnetic characteristic in the temperature lower than the antiferromagnetic transition temperature (TN).