形貌可控纳米SrFe_(12)O_(19)的制备及其磁性能  

Synthesis and Magnetic Property of Shape-Controlled Nano-SrFe_(12)O_(19)

作　　者：李巧玲[1] 常传波[1] 景红霞[1] 杨晓峰[1] 

机构地区：[1]中北大学理学院化学系,太原030051

出　　处：《物理化学学报》2010年第6期1699-1704,共6页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金(20571066;20871108)资助项目~~

摘　　要：以FeCl3为原料,NaOH作为沉淀剂,通过化学沉淀法,制备出球状的Fe(OH)3中间体,同时以FeCl2为原料,采用化学沉淀法,分别使用NH3·H2O、Na2CO3和NaOH作为沉淀剂制得了不同形貌的中间体,利用柠檬酸法在中间体表面包裹锶的柠檬酸络合物,煅烧后分别制得了球形、纺锤体及棒状的纳米SrFe12O19.利用X射线衍射(XRD)和透射电镜(TEM)等测试手段对不同形貌的纳米SrFe12O19进行表征,并利用振动样品磁强计(VSM)对磁性能进行研究.结果表明:在用化学沉淀-柠檬酸法制备SrFe12O19的过程中,铁盐的种类以及沉淀剂的碱性对中间体的物相和SrFe12O19的形貌有着至关重要的影响.当原料为Fe3+时,制得了球形的纳米SrFe12O19;当原料为Fe2+时,利用碱性不同的沉淀剂可制得不同形貌的纳米SrFe12O19.随着沉淀剂碱性的增加,所得SrFe12O19的长径比增加,形貌各向异性增加.SrFe12O19的矫顽力(Hc)主要取决于粒子的各向异性,各向异性越大,矫顽力越大,饱和磁化强度(Ms)随着样品的各向异性的增加也有所增加,以FeCl2为原料,NaOH作为沉淀剂时制得的棒状SrFe12O19的矫顽力和饱和磁化强度最大分别为458.2kA·m-1和64.2A·m2·kg-1.FeCl3 and NaOH were used as raw material and precipitator respectively to prepare a spherical Fe（OH）3 intermediate by chemical precipitation.FeCl2 and other precipitators（Na2CO3,NH3·H2O and NaOH） were also used to prepare shape-controlled intermediates via co-precipitation.The intermediates were then covered with a citric acid and Sr complex by the citrate acid method.Spherical,spindly and rod-like nano-SrFe12O19 particles were obtained after calcination of the covered precursors.The shape-controlled nano-SrFe12O19 particles were characterized by X-ray diffraction（XRD）,transmission electron microscopy（TEM） and the magnetic properties of the samples were studied using a vibrating sample magnetometer（VSM）.Results showed that the type of ferric salt and the alkalinity of the precipitator greatly influenced the phase of the intermediate and the morphology of the SrFe12O19 particles.Spherical nano-SrFe12O19 particles were obtained when Fe3＋ was used as a raw material,and shape-controlled nano-SrFe12O19 particles were obtained when Fe2＋ was used as a raw material together with precipitators of different alkalinity.The slenderness ratio and shape-anisotropy of the samples increase as the alkalinity of the precipitator increases.The coercivity（Hc） of SrFe12O19 is mainly dependent on the anisotropy of the particle.The coercivity and the saturation magnetization（Ms） of SrFe12O19 increase as the anisotropy of the samples increases.The coercivity and the Ms of the rod-like SrFe12O19 particles obtained using FeCl2 and NaOH were optimal 458.2 kA·m-1 and 64.2 A·m·2kg-1,respectively.

关 键 词：形貌可控 纳米SrFe12O19 化学沉淀-柠檬酸法 磁性能 

分 类 号：TB383.1[一般工业技术—材料科学与工程] O614[理学—无机化学]