Magnetoresistance and magnetic properties of Fe3O4 nanoparticle compacts
Wang Hai (王海)a, Zhao Hong-Wu (赵宏武)a, Wang Chang-Sheng (王常生)a, Wang Yin-Jun (王荫君)a, Zhan Wen-Shan (詹文山)a, Li Feng-Ying (李凤英)b, Jin Chang-Qing (靳常青)b, Meng Fan-Bin (孟凡斌)c, Li Yang-Xian (李养贤)c
a State Key Laboratory of Magnetism, Institute of Physics and Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100080, China; b Institute of Physics and Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100080, China; c Material Test Center, Hebei University of Technology, Tianjin 300130, China
Abstract In this paper, we report on the magnetic properties of Fe3O4 nanoparticles with different grain sizes under different pressures. In all the samples, the saturated magnetization Ms shows a linear decrease with increasing pressure. The thickness of the magnetic dead layer on the nanoparticle surface under different pressures was roughly estimated, which also increases with increasing pressure. The transport measurements of the nanoparticle Fe3O4 compacts show that the low-field magnetoresistance (MR) value is insensitive to the grain size in a wide temperature range; however, the high-field MR value is dependent on grain size, especially at low temperatures. These experimental results can be attributed to the different surface states of the nanoparticles.
Received: 03 July 2001
Revised: 29 September 2001
Accepted manuscript online:
(Magnetic properties of interfaces (multilayers, superlattices, heterostructures))
Fund: Project supported by the National Natural Science Foundation of China (Grant Nos. 59928101 and 59871063).
Cite this article:
Wang Hai (王海), Zhao Hong-Wu (赵宏武), Wang Chang-Sheng (王常生), Wang Yin-Jun (王荫君), Zhan Wen-Shan (詹文山), Li Feng-Ying (李凤英), Jin Chang-Qing (靳常青), Meng Fan-Bin (孟凡斌), Li Yang-Xian (李养贤) Magnetoresistance and magnetic properties of Fe3O4 nanoparticle compacts 2002 Chinese Physics 11 178
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