Size Effects on Magnetic Properties of Ni0.5Zn0.5Fe2O4 Prepared by Sol-Gel Method

Autor: Min Zhang, Zhenfa Zi, Qiangchun Liu, Peng Zhang, Xianwu Tang, Jie Yang, Xuebin Zhu, Yuping Sun, Jianming Dai
Jazyk: angličtina
Rok vydání: 2013
Předmět:
Zdroj: Advances in Materials Science and Engineering, Vol 2013 (2013)
Druh dokumentu: article
ISSN: 1687-8434
1687-8442
DOI: 10.1155/2013/609819
Popis: Ni0.5Zn0.5Fe2O4 particles with different particle sizes have been synthesized by sol-gel method. X-ray diffraction results show that all the samples are pure cubic spinel structure with their sizes ranging from 9 to 96 nm. The lattice constant significantly decreases with further increasing annealing temperature. The magnetic measurements show superparamagnetic nature below the particle size of 30 nm, while others show ferrimagnetic nature above the corresponding blocking temperature. The blocking temperature increases with the increase in particle size, which can be explained by Stoner-Wohlfarth theory. The saturation magnetization increases as the particle size increases, which can be explained by the cation redistribution on tetrahedral A and octahedral B sites and the domain wall motion. The variation of coercivity as a function of particle size is based on the domain structure.
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