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以聚乙烯吡咯烷酮、硝酸锂、硝酸锌和硝酸铁为主要原料,通过静电纺丝技术结合后期的热处理制备了直径在50～100 nm的单相Li0.5-0.5xZnxFe2.5-0.5xO4(x=0.0,0.2,0.3,0.4,0.5,0.8)纳米纤维.利用热重-差热分析、X射线衍射、场发射扫描电子显微镜、透射电子显微镜和振动样品磁强计研究了前驱体纤维的热分解过程以及焙烧温度和化学成分对所得纳米纤维样品的晶体结构、微观形貌和磁性能的影响.结果表明:前驱体纤维经350℃焙烧后,纯相晶态的LiZn铁氧体纳米纤维基本形成.当焙烧温度由350℃升高到600℃,Li0.35Zn0.3 Fe2.35O4纳米纤维的平均晶粒尺寸由13.0 nm增大到47.5 nm,微观形貌逐渐向链状结构演化,比饱和磁化强度由39.7 A·m2·kg-1单调递增到84.5 A·m2·kg-1,而矫顽力先增大后减小,在550℃时达到最大值12.6 kA·m-1,其单畴临界尺寸约为35 nm.随着Zn含量x的增加,所制备的LiZn铁氧体纳米纤维的晶格常数近似呈线性增长,符合Vegard定律,矫顽力从x=0.0时的17.1 kA·m-1逐步减小到x=0.8时的2.4 kA·m-1,比饱和磁化强度Ms先增大后减小,在x=0.3时达到一个最大值74.7 A·m2·kg-1.与相似条件下制备的LiZn铁氧体纳米粒子相比,LiZn铁氧体纳米纤维由于其形状各向异性,而表现出相对较高的矫顽力.
A series of Li0.5-0.5xZnxFe2.5-0.5xO4 (x) nanocrystals with diameter of 50 ~ 100 nm were prepared by electrospinning combined with the later heat treatment with polyvinylpyrrolidone, lithium nitrate, zinc nitrate and ferric nitrate as the main raw materials. = 0.0, 0.2, 0.3, 0.4, 0.5, 0.8) nanofibers.The thermal properties of the precursor fibers were investigated by thermogravimetric-differential thermal analysis, X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy and vibrating sample magnetometers The decomposition process, the calcination temperature and the chemical composition on the crystal structure, the micro-morphology and the magnetic properties of the obtained nanofibers were investigated. The results showed that the pure LiZn ferrite nanofibers .The average grain size of Li0.35Zn0.3Fe2.35O4 nanofibers increased from 13.0 nm to 47.5 nm when the calcination temperature increased from 350 ℃ to 600 ℃, and the microstructure gradually evolved to a chain structure, The magnetization increases monotonously from 39.7 A · m 2 · kg -1 to 84.5 A · m 2 · kg -1, while the coercivity first increases then decreases and reaches the maximum value of 12.6 kA · m -1 at 550 ℃. The domain critical dimension is about 35 nm. With the increase of Zn content x, the prepared LiZn ferrite nanofibers , The lattice constant increases approximately linearly, which is consistent with Vegard’s law. The coercivity gradually decreases from 17.1 kA · m-1 at x = 0.0 to 2.4 kA · m-1 at x = 0.8, and the specific saturation magnetization Ms Increases and then decreases, reaching a maximum value of 74.7 A · m2 · kg-1 at x = 0.3.Compared with LiZn ferrite nanoparticles prepared under similar conditions, LiZn ferrite nanofibers, due to their shape-oriented The opposite sex, while showing a relatively high coercivity.