First-order phase transition characteristic of the high temperature metal-semiconductor transition in Ca(2)CoO(3) (0.62) CoO(2)

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	First-order phase transition characteristic of the high temperature metal-semiconductor transition in Ca(2)CoO(3) (0.62) CoO(2)
	J. G. Cheng; Y. Sui; Y. Wang; X. J. Wang; W. H. Su
	2009
发表期刊	Applied Physics a-Materials Science & Processing
ISSN	0947-8396
卷号	94 期号:4 页码:911-916
摘要	Transportation and thermodynamic properties of misfit-layered polycrystalline [Ca(2)CoO(3)](0.62)[CoO(2)] were measured in order to clarify the nature of metal- semiconductor transition (MST) at T (MS)a parts per thousand 400 K, above which the simultaneous decrease of resistivity and increase of thermopower with temperature give rise to a great enhancement of thermoelectric power factor up to 1000 K. A first-order phase transition characteristic around T (MS) was revealed by anomalies of resistivity, differential scanning calorimetry, and thermal expansion. The first-order characteristic of the MST can be rationalized from the Virial theorem at an itinerant to localized electron transition in the narrow e (T) band within the [CoO(2)] plane. Above T (MS), the reduction of the retained delocalized states within the matrix of localized states and the enhancement of charge carrier effective mass with increasing temperature might account for the considerable enhancement of the thermopower.
部门归属	[cheng, jinguang; sui, yu; wang, yang; wang, xianjie; su, wenhui] harbin inst technol, ctr condensed matter sci & technol, dept phys, harbin 150001, peoples r china. [sui, yu; su, wenhui] chinese acad sci, int ctr mat phys, shenyang 110016, peoples r china.;sui, y (reprint author), harbin inst technol, ctr condensed matter sci & technol, dept phys, harbin 150001, peoples r china;suiyu@hit.edu.cn
关键词	Thermoelectric Properties Ca3co4o9 Ceramics System
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文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/31848
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	J. G. Cheng,Y. Sui,Y. Wang,et al. First-order phase transition characteristic of the high temperature metal-semiconductor transition in Ca(2)CoO(3) (0.62) CoO(2)[J]. Applied Physics a-Materials Science & Processing,2009,94(4):911-916.
APA	J. G. Cheng,Y. Sui,Y. Wang,X. J. Wang,&W. H. Su.(2009).First-order phase transition characteristic of the high temperature metal-semiconductor transition in Ca(2)CoO(3) (0.62) CoO(2).Applied Physics a-Materials Science & Processing,94(4),911-916.
MLA	J. G. Cheng,et al."First-order phase transition characteristic of the high temperature metal-semiconductor transition in Ca(2)CoO(3) (0.62) CoO(2)".Applied Physics a-Materials Science & Processing 94.4(2009):911-916.