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The anomalous thermal properties of glasses at low temperaturesWhile experimentally there is great regularity below 1 deg K in the behavior of a particular thermal property for all amorphous dielectrics it is not understood why these properties should differ from those of crystalline dielectrics, since it would seem that at low temperatures long-wavelength elastic waves, similar in both cases, would determine the thermal properties. A model involving systems having very few levels is used in the present study, although the relation between the model's systems and the nature of the glassy state is not known. It is shown, among other effects, that: specific heat measurements above 0.1 K indicate a distribution of local modes independent of energy; ultrasonic velocity measurements give information about phonon-local mode coupling parameters; and thermal expansion and far infrared experiments indicate a phonon-assisted tunneling model.
Document ID
19770048867
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Pohl, R. O.
(Cornell University Ithaca, N.Y., United States)
Salinger, G. L.
(Rensselaer Polytechnic Institute, Troy, N.Y., United States)
Date Acquired
August 8, 2013
Publication Date
October 15, 1976
Publication Information
Publication: New York Academy of Sciences
Subject Category
Nonmetallic Materials
Accession Number
77A31719
Funding Number(s)
CONTRACT_GRANT: NGL-33-018-003
CONTRACT_GRANT: AT(11-1)-3151
Distribution Limits
Public
Copyright
Other

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