Thermal conductivity of electron-doped CaMnO(3) perovskites: Local lattice distortions and optical phonon thermal excitation

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	Thermal conductivity of electron-doped CaMnO(3) perovskites: Local lattice distortions and optical phonon thermal excitation
	Y. Wang; Y. Sui; X. J. Wang; W. H. Su; X. Y. Liu; H. J. Fan
	2010
发表期刊	Acta Materialia
ISSN	1359-6454
卷号	58 期号:19 页码:6306-6316
摘要	The thermal transport properties of a series of electron-doped CaMnO(3) perovskites have been investigated. Throughout the temperature range 5-300 K, phonon thermal conductivity is dominant, and both electron and spin wave contributions are negligible. The short phonon mean free paths in this system result in the relatively low thermal conductivities. The strong phonon scatterings stem from the A-site mismatch and bond-length fluctuations induced by local distortions of MnO(6) octahedra. The thermal conductivity in the magnetically ordered state is enhanced as a result of the decrease in spin-phonon scattering. The results also indicate that above the magnetic ordering temperature, observable thermal excitation of optical phonons occurs. The contribution of optical phonons to thermal conductivity becomes non-negligible and is proposed to play an important role in the glass-like thermal transport behavior (i.e. positive temperature dependence of the thermal conductivity) in the paramagnetic state. These features can be understood in terms of an expression of thermal conductivity that includes both acoustic and optical phonon terms. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
部门归属	[wang, yang; sui, yu; wang, xianjie; su, wenhui] harbin inst technol, dept phys, ccmst, harbin 150001, peoples r china. [wang, yang; fan, hong jin] nanyang technol univ, sch phys & math sci, div phys & appl phys, singapore 637371, singapore. [liu, xiaoyang] jilin univ, coll chem, state key lab inorgan synth & preparat chem, changchun 130012, peoples r china. [sui, yu] acad sinica, int ctr mat phys, shenyang 110015, peoples r china.;sui, y (reprint author), harbin inst technol, dept phys, ccmst, harbin 150001, peoples r china;suiyu@hit.edu.cn fanhj@ntu.edu.sg
关键词	Manganite Perovskite Thermal Conductivity Spin-phonon Scattering Mno(6) Distortion Optical Phonon Colossal Magnetoresistance La1-xsrxmno3 Crystals Manganite Perovskites Heat-transport Transition Chemistry Physics Oxides Series La
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文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/31543
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	Y. Wang,Y. Sui,X. J. Wang,et al. Thermal conductivity of electron-doped CaMnO(3) perovskites: Local lattice distortions and optical phonon thermal excitation[J]. Acta Materialia,2010,58(19):6306-6316.
APA	Y. Wang,Y. Sui,X. J. Wang,W. H. Su,X. Y. Liu,&H. J. Fan.(2010).Thermal conductivity of electron-doped CaMnO(3) perovskites: Local lattice distortions and optical phonon thermal excitation.Acta Materialia,58(19),6306-6316.
MLA	Y. Wang,et al."Thermal conductivity of electron-doped CaMnO(3) perovskites: Local lattice distortions and optical phonon thermal excitation".Acta Materialia 58.19(2010):6306-6316.