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Thermal diffusivity of diamond films using a laser pulse techniquePolycrystalline diamond films were deposited using a microwave plasma-enhanced chemical vapor deposition process. A laser pulse technique was developed to measure the thermal diffusivity of diamond films deposited on a silicon substrate. The effective thermal diffusivity of a diamond film on silicon was measured by observing the phase and amplitude of the cyclic thermal waves generated by laser pulses. An analytical model is presented to calculate the effective in-plane (face-parallel) diffusivity of a two-layer system. The model is used to reduce the effective thermal diffusivity of the diamonds/silicon sample to a value for the thermal diffusivity and conductivity of the diamond film. The average effective diffusivity values are 1.47 + or - 0.03 and 1.83 + or - 0.10 yielding thermal diffusivity values of 7.46 + or - 0.90 and 7.33 + or - 0.70 sq cm/s respectively, for the two samples; the calculated thermal con ductivity values are 13.50 and 13.28 W/cmK, which are better than that of type 1a natural diamond. The phase and amplitude measurements give similar results.
Document ID
19900049170
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Albin, Sacharia
(Old Dominion University Norfolk, VA, United States)
Winfree, William P.
(Old Dominion Univ. Norfolk, VA, United States)
Crews, B. Scott
(NASA Langley Research Center Hampton, VA, United States)
Date Acquired
August 14, 2013
Publication Date
June 1, 1990
Publication Information
Publication: Electrochemical Society, Journal
Volume: 137
ISSN: 0013-4651
Subject Category
Solid-State Physics
Accession Number
90A36225
Distribution Limits
Public
Copyright
Other

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