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采用溶胶-凝胶法结合静电纺丝技术成功制备了直径在100nm左右的Ni0.3Cu0.2Zn0.5Fe2O4铁氧体纳米纤维.并使用热重-差热分析(TG-DTA)、X射线衍射(XRD)、傅立叶红外变换光谱(FT-IR)、场发射扫描电镜(FE-SEM)、透射电镜(TEM)和振动样品磁强计(VSM)对电纺的复合纳米纤维及其焙烧产物进行了表征.实验结果表明,复合纳米纤维在450℃焙烧时,立方尖晶石结构就已基本形成.随着焙烧温度的升高,纳米纤维中Ni0.3Cu0.2Zn0.5Fe2O4晶粒的尺寸逐渐增大,纤维表面也越发粗糙,其形貌逐渐向项链状结构转变.与此同时,目标纳米纤维的比饱和磁化强度(Ms)单调增大,而矫顽力(Hc)则呈现先增大后减小的趋势,在650℃达到最大值,这暗示以纳米纤维形式存在的Ni0.3Cu0.2Zn0.5Fe2O4的单畴临界尺寸可能在53nm左右.此外,发现在单畴临界尺寸以下,Ni0.3Cu0.2Zn0.5Fe2O4纳米纤维的矫顽力与其平均晶粒尺寸(D)的0.71次方成正比,即Hc∝D0.71,较好地符合随机各向异性模型所预测的结果Hc∝D2/3.
Ni0.3Cu0.2Zn0.5Fe2O4 ferrite nanofibers with a diameter of about 100nm were successfully prepared by the sol-gel method combined with electrospinning technology. The thermogravimetry-differential thermal analysis (TG-DTA), X-ray diffraction XRD, FT-IR, FE-SEM, TEM and VSM were used to characterize the electrospun composite nanofibers and their roasted products Characterization.The experimental results show that the cubic spinel structure has basically formed when the composite nanofibers are roasted at 450 ° C. The size of Ni0.3Cu0.2Zn0.5Fe2O4 grains in nanofibers increases with the increase of calcination temperature , The fiber surface becomes more rough and its morphology gradually changes to the necklace structure.At the same time, the specific saturation magnetization (Ms) of the target nanofibers monotonically increases, while the coercivity (Hc) increases first and then decreases The small trend, reaching a maximum at 650 ℃, suggests that the critical size of single domain of Ni0.3Cu0.2Zn0.5Fe2O4 in the form of nanofibers may be about 53nm.In addition, it is found that below the critical domain size of single domain, Ni0.3Cu0. The coercivity of 2Zn0.5Fe2O4 nanofibers and the average grain size (D) of 0.71 Ratio, i.e. HcαD0.71, in good agreement with the results predicted by the random anisotropic model HcαD2 / 3.