Study On Multi - Iron Properties And Doping Modification Of SmFeO <3> /

Multiferroic material is a new type of functional material which will be widely used in the information storage, spintronics, etc. Single-phase multiferroics is such materials in which two or more properties of fundamental ferroicities （ferromagnetism, ferroelectricity, and ferroelasticity） coexist. The coexistence of several order parameters in multiferroics makes the mutual control of different ferroic properties. In order to realize the strong magnetoelectric coupling, we study the materials whose ferroelectric and magnetic properties are intrinsic association. We discussed the magnetic, dielectric, and ferroelectric in SmFeO3（SFO） and SmFe1-xMnx03ceramics. The main research works are as follows.The samples of SFO ceramics were prepared using sol-gel method. The crystal structures of SFO ceramics annealed at various temperatures were characterized by X-ray diffraction （XRD SHK7000）, FE-SEM （Field emission scanning electron microscope, Hitachi, S-4800）. The magnetic measurements showed antiferromagnetic transition temperature Tn-720K, about50K higher than that reported in the literature. The dielectric measurement results revealed the sample had a anomaly peak-720K, which is ascribed to ferroelectric transition. Further more, we also measured the ferroelectricity of the samples at room temperature.We studied the influence of Fe2%more （Fe+2） and Fe2%less （Fe.2） on the properties of SmFeO3ceramics samples. We found no obvious differences from the samples’XRD patterns. The magnetic measurements showed significant differences between Fe+2sample and Fe₂sample. The ferroelectric measurements reveal that the ferroelectric hysteresis loop of the Fe+2shows lower current density than that of SmFeO3sample. In addition, the dielectric measurements show that Fe+2sample has one more anomaly peak-600K.SmFe1-xMnXO3（x=0,0.1,0.2,0.3） ceramics were prepared by the conventional solid-state reaction method. It was found all the SmFe1-xMnxO3ceramics were orthorhombic structures with Pbnm space groups. The magnetic measurements showed the antiferromagnetic transition temperature of SmFe1-xMnx03ceramics were moving to low temperature with the increase of Mn content. At the same time, the dielectric measurements also showed the ferroelectric transition temperatures also moved to the low temperature with the increase of Mn content.