退火温度对水热合成的纳米晶Ni_(0.6)Zn_(0.4)Fe_2O_4铁氧体磁性能的影响

采用水热法在180℃下合成纳米级的尖晶石相的Ni0.6Zn0.4Fe2O4铁氧体材料,在空气中退火温度分别为600、800、1000℃.使用X射线衍射(XRD)、红外光谱(FTIR)、扫描电镜(SEM)和振动样品磁强计(VSM)分别表征NiZn铁氧体纳米粉体的相组成、微结构以及磁性能.XRD衍射谱和FTIR谱表明:未退火和退火的纳米晶NiZn铁氧体皆为单一尖晶石相;退火温度对晶格常数基本无影响,主要提高了致密度以及使晶粒尺寸得到长大;样品的饱和磁化强度随着退火温度的提高逐渐增大到1 000℃时的58.75 emu/g;样品的矫顽力与未退火的样品相比,先增加后减小,其矫顽力主要取决于样品的微结构.

Annealing temperature effect on magnetic properties of Ni0.6 Zn0.4Fe2O4 ferrite nano-crystalline via hydrothermal synthesis

Nano-scale NiZn spinel ferrite powder was synthesized at 180 ℃ by hydrothermal synthesis method,and then it was annealed at 600,800 and 1 000 ℃ in air respectively.Its morphology,microstructure and magnetic properties were characterized by X-ray diffraction(XRD),fourier transform infrared spectroscopy(FTIR),scanning transmission electron microscopy(SEM) and vibrating sample magnetometer(VSM),respectively.XRD and FTIR spectroscopies show that non-annealing and annealing Ni0.6Zn0.4Fe2O4 ferrite samples all are the single spinel phase.Annealing temperature has little effect on the lattice constant and mainly has influence on the particle size.The saturation magnetization of the samples was improved with the increasing annealing temperature,exhibiting with 58.75 emu/g at 1 000 ℃.As compared to the non-annealing powders,the coercive force of the samples firstly increased with the increasing annealing temperature,then decreased as the annealing temperature increased,the coercive force of the samples mainly depended on its microstructure.