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采用溶胶-凝胶法制备出钙钛矿型纳米BaFeO3粉末,利用X射线衍射(XRD)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)分析研究了其微观结构及形貌,结果表明:胶体试样经800℃退火处理后,形成了20 nm左右的钙钛矿型BaFeO3粉末,其(110)面晶面间距为0.280 nm左右,(100)面晶面间距为0.401 nm左右.利用振动样品磁强计(VSM)研究了纳米BaFeO3粉末的室温铁磁性能,测量结果表明:在室温条件下,纳米BaFeO3粉末具有完整闭合的磁滞回线,具有较小的矫顽力和较低的饱和磁化强度,呈现出明显的弱铁磁性,且铁磁性随退火温度的变化明显.钙钛矿型纳米BaFeO3的铁磁性主要归因于Fe3+-O-Fe4+之间的氧空位.
The perovskite-type nanosized BaFeO3 powders were prepared by sol-gel method. The microstructure and morphology of the nanosized BaFeO3 powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) After annealing at 800 ℃ for 4h, the perovskite-type BaFeO3 powders with the size of about 110 nm were formed, the distance between the (110) plane and the (100) plane was about 0.401 nm, The room-temperature ferromagnetic properties of nanometer BaFeO3 powders were investigated by the sample magnetometer (VSM). The results show that the nanocrystalline BaFeO3 powders have a complete closed hysteresis loop at room temperature with low coercivity and low The saturation magnetization shows obvious weak ferromagnetism, and the ferromagnetism changes obviously with the annealing temperature.The ferromagnetism of perovskite nano-BaFeO3 is mainly attributed to the oxygen vacancies between Fe3 + -O-Fe4 +.