钙钛矿型纳米BaFeO3的制备、结构表征及铁磁性研究  

Preparation,structure and ferromagnetic properties of perovskite BaFeO_3 nanocrystals

作　　者：刘妍妍[1] 刘发民[1] 石霞[1] 丁芃[1] 传仓 

机构地区：[1]北京航空航天大学理学院物理系,北京100191

出　　处：《物理学报》2008年第11期7274-7278,共5页Acta Physica Sinica

基　　金：航空科学基金(批准号:2003ZG51069);国防基础研究基金资助的课题~~

摘　　要：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 BaFeO3 nano-powder has been synthesized by sol-gel method. The micro-structure and morphology of BaFeO3 nano-powder have been characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and high resolution transmission electron microscopy （ HRTEM）. The results showed that the samples annealed at 800℃ formed the perovskite-type BaFeO3 with grain size of about 20 nm and the （110） and （100） spacings of about 0.280 nm and 0.401 nm, respectively. The room temperature magnetic properties of samples have been measured on vibrating sample magnetometer （VSM）. It is shown that the BaFeO3 nano-powder has a complete hysteresis loop, which means that BaFeO3 powder possess significant weak ferromagnetism at room temperature, and this property changes obviously with the annealing temperature. Ferromagnetism of perovskite BaFeo3 nano-powder mainly originates from oxygen vacancy among Fe^3 ＋ -O-Fe^4＋ .

关 键 词：溶胶-凝胶法 钙钛矿型纳米BaFeO3 铁磁性 氧空位 

分 类 号：O737[理学—晶体学]