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Author Whitmore, D. H.
Sponsorship USDOE
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Publisher American Institute of Physics (AIP)
Language English
Subject Keyword METALS, CERAMICS, AND OTHER MATERIALS ♦ CERAMICS ♦ CRYSTALS ♦ DECOMPOSITION ♦ DIFFUSION ♦ ELECTRONICS ♦ ELECTRONS ♦ ENERGY ♦ EXCITATION ♦ GASES ♦ HEAT TRANSFER ♦ HIGH TEMPERATURE ♦ MOLECULES ♦ PHASE DIAGRAMS ♦ POROSITY ♦ SOUND ♦ THERMAL CONDUCTIVITY ♦ THERMAL STRESSES
Abstract The problem of the anomalous increase in the observed thermal conductivity of single-phase ceramics at high temperatures is considered. At temperatures above the onset of this anomalous rise, account is taken of the possibility that phonon, electronic, and radiative heat transfer, as well as transport of thermal energy by electron-hole pairs, excitons, and dissociated gas molecules, may operate simultaneously and individually contribute significantly to the total heat flow. On the basis of reliable conductivity data on nonporous monocrystals of single-phase ceramics, estimations are made of the magnitades of these high-temperature components which reveal that excited states of low excitation energy may occur in certain ceramics. In these instances, such excited energy-carrying states are able to diffuse down the temperature gradient in the specimen thereby producing a non-negligible contribution to its observed thermal conductivity.
ISSN 00218979
Educational Use Research
Learning Resource Type Article
Publisher Date 1960-01-01
Publisher Department Northwestern Univ., Evanston, Ill.
Journal Journal of Applied Physics
Volume Number 31
Issue Number 6
Organization Northwestern Univ., Evanston, Ill.


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