Electrical properties and phase transition of CoFe2O4 nanocrystals under pressure

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	Electrical properties and phase transition of CoFe2O4 nanocrystals under pressure
	Z. Y. Wu; Z. X. Bao; L. Cao; C. X. Liu; Q. S. Li; S. S. Xie; B. S. Zou
	2003
发表期刊	Journal of Applied Physics
ISSN	0021-8979
卷号	93 期号:12 页码:9983-9987
摘要	The electric resistance CoFe2O4 nanocrystals of different sizes, obtained by the coprecipitation method was investigated under pressure up to 20 GPa in a diamond anvil cell at ambient temperature. The experimental results indicate that the phase transition (from the spinel to a tetragonal structure) takes place at 7.5 and 12.5 GPa for 6 and 80 nm, nanocrystals, respectively, in agreement with the prediction of scaling theory of the phase transition of nanocrystals. The relatively low transition pressure for CoFe2O4 is related to the high d-electron coupling between magnetic ions and to the small band gap in CoFe2O4 as compared to the other spinel ferrites. These results are discussed in terms of decreasing band gap with increasing pressure. The smaller the size of nanocrystals, the higher the phase transition pressure. The resistance of CoFe2O4 nanocrystal decreases exponentially under pressure, according to Rproportional toexp(-CP), where C=0.7634 GPa(-1) for large nanocrystals (80 nm) and C=0.5124 GPa(-1) for CoFe2O4 of 6 nm. (C) 2003 American Institute of Physics.
部门归属	chinese acad sci, inst phys, nanoscale phys & device lab, beijing 100080, peoples r china. beijing inst technol, sch chem engn & mat sci, beijing 100080, peoples r china. peking univ, state key lab rare earth mat chem & applicat, beijing 100871, peoples r china. chinese acad sci, int ctr mat phys, shenyang 110615, peoples r china.;zou, bs (reprint author), chinese acad sci, inst phys, nanoscale phys & device lab, pob 603, beijing 100080, peoples r china
关键词	Cdse Nanocrystals Transformation Temperature Parameters Particles Dynamics Energies Wurtzite Si
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WOS记录号	WOS:000183288900088
引用统计	被引频次：32[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/36087
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	Z. Y. Wu,Z. X. Bao,L. Cao,et al. Electrical properties and phase transition of CoFe2O4 nanocrystals under pressure[J]. Journal of Applied Physics,2003,93(12):9983-9987.
APA	Z. Y. Wu.,Z. X. Bao.,L. Cao.,C. X. Liu.,Q. S. Li.,...&B. S. Zou.(2003).Electrical properties and phase transition of CoFe2O4 nanocrystals under pressure.Journal of Applied Physics,93(12),9983-9987.
MLA	Z. Y. Wu,et al."Electrical properties and phase transition of CoFe2O4 nanocrystals under pressure".Journal of Applied Physics 93.12(2003):9983-9987.