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
刊名	Acta Materialia
	2010
卷号	58 期号:19 页码:6306-6316
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
ISSN号	1359-6454
中文摘要	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.
原文出处	://WOS:000283807900010
公开日期	2012-04-13
内容类型	期刊论文
源URL	[http://210.72.142.130/handle/321006/31543]
专题	金属研究所_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.