摘要
采用静电纺丝技术结合后期的热处理制备了具有多孔结构的Ni1-xZnxFe2O4（x=0-0.8）超细纤维.利用X射线衍射（XRD）、傅里叶变换红外光谱（FTIR）、场发射扫描电镜（FESEM）、低温N2吸附-脱附和振动样品磁强计（VSM）对纤维样品的晶体结构、微观形貌、孔特征和室温磁性能进行了研究.结果表明,550℃焙烧2 h得到的多孔Ni1-xZnxFe2O4超细纤维均为单相尖晶石结构,平均粒径约为25-30 nm,纤维直径主要分布在200-500 nm之间,且具有较大的长径比;所制备的Ni0.5Zn0.5Fe2O4多孔纤维的孔结构主要以狭缝状介孔为主,其平均孔径约为11 nm;随着Zn含量x由0增加0.8,Ni1-xZnxFe2O4纤维的晶格常数a线性增大,A位的红外特征振动频率单调递减,矫顽力由13.8 kA/m逐步减小到2.3 kA/m,比饱和磁化强度先增大后减小,在x=0.4时达到最大值66.8 A.m2/kg.与相近尺寸的Ni-Zn铁氧体纳米粒子相比,Ni-Zn铁氧体超细纤维由于其形状各向异性而表现出更高的矫顽力.
Porous Ni1-xZnxFe2O4（x=0-0.8） ultrafine fibers were prepared by electrospinning technique and subsequent calcination process.The crystal structure,micromorphology,pore character and room-temperature magnetic properties of the samples were investigated by means of XRD,FTIR,FESEM,low-temperature N2 adsorption-desorption and VSM techniques,respectively.The results show that the obtained porous Ni1-xZnxFe2O4 ultrafine fibers calcined at 550℃ for 2 h are single-phase spinel structure with an average grain size of 25-30 nm.These ultrafibers have diameters in the range of 200–500 nm and a large aspect ratio.N2 adsorption-desorption analysis indicate that the pore structure of as-prepared Ni0.5Zn0.5Fe2O4 porous fibers mainly consists of slit-like mesopores with a mean pore diameter of about 11 nm.With the increase of Zn content（x=0 to x=0.8）,the lattice constant of Ni1-xZnxFe2O4 ultrafine fibers increases linearly and complies well with Vegard’s law,and the infrared vibrational frequencies corresponding to tetrahedral sites shift toward lower wavenumber.The coercivity of the samples gradually decreases from 13.8 kA/m（x=0） to 2.3 kA/m（x=0.8）,whereas the specific saturation magnetization increases initially,reaches a maximun value of 66.8 A.m2/kg at x=0.4 and then decreases with further increase of Zn content.It is found that the synthesized Ni-Zn ferrite untrafine fibers exhibit relatively high coercivity due to their high shape anisotropy compared with the nanoparticle counterparts with similar size.These porous Ni-Zn ferrite untrafine fibers have potential application in many fields such as sensitive devices,microwave absorbers,and catalysts.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
2012年第4期363-368,共6页
Journal of Inorganic Materials
基金
高等学校博士学科点专项科研基金(20103227110006)
江苏省普通高校研究生科研创新计划项目(CX09B-192Z)
江苏省青蓝工程项目
江苏省高校自然科学研究项目(11KJB430006)~~
