煅烧工艺和稀土掺杂对钡铁氧体微纳米结构的影响

Effect of Calcination Technology and Rare Earth Doping on the Micro/nano Structure of Barium Ferrite

采用静电纺丝技术,以PVP的冰醋酸溶液为助纺剂,以Ba(NO3)2、Fe(NO3)3·9H2O、La(NO3)3·6H2O和C6H8O7·H2O为基本原料获得了BaFe12O19/PVP一维复合纤维,并利用SEM、XRD对复合纤维煅烧前、后样品进行形貌和物相的表征。结果表明:煅烧前,BaFe12O19/PVP复合纤维平均直径为350～500nm。经800,850℃煅烧2h,均生成了六方晶系的M型BaFe12O19相。随着升温速率的提高,依次形成了棒状、片状、颗粒状、八面体锥状的BaFe12O19。掺杂稀土元素镧并煅烧后,产物除BaFe12O19相外,还有少量LaFe12O19相,但对结构和形貌无明显影响。

BaFe12O19 /PVP composite fibers were prepared by electrostatic spinning technique with Ba(NO3)2 , Fe(NO3)3 ·9H2O, La(NO3)3 ·6H2O and C6H8O7 ·6H2O as starting materials and with PVP and acetic acid as a spinning aid. The crystal structure and morphology of the samples before and after calcination were characterized by means of XRD and SEM. The results show that BaFe12O19/PVP composite fibers have an average diameter of 350 ～ 500 nm before calcined. M-type BaFe12O19 are obtained after calcining BaFe12O19 /PVP composite fibers at 800 ℃ and 850 ℃ for about 2 h. With the increase of the heating rate, BaFe12O19 forms, whose structure are rod, sheet, granular and octahedral subulate in turn. After lanthanum doping and calcinations there are a small number of LaFe12O19 besides BaFe12O19 . There is no significant effect on the structure and morphology of BaFe12O19 after doped rare earth elements.