Current Search: Ammonia--Analysis (x)
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Title
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TEMPERATURE AND VOLUME DEPENDENCE OF LATTICE VIBRATIONAL FREQUENCIES FOR SOLID AMMONIA I.
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Creator
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NYE, CHARLES LEE., Florida Atlantic University
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Abstract/Description
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The frequencies of three lattice vibrational nodes of solid ammonia I were measured as functions of temperature and molar volume, via Raman spectroscopy. Calculated Gruneisen parameters of 2.6, 2.4, and 0.8, for modes with frequencies near 108 cm^-1 , 140 cm^-1 and 306 cm^-1 , respectively, identify the first two modes to be translational and the third librational in accordance with previous assignments. The Gruneisen parameter of the libration is lower than expected for purely octopolar...
Show moreThe frequencies of three lattice vibrational nodes of solid ammonia I were measured as functions of temperature and molar volume, via Raman spectroscopy. Calculated Gruneisen parameters of 2.6, 2.4, and 0.8, for modes with frequencies near 108 cm^-1 , 140 cm^-1 and 306 cm^-1 , respectively, identify the first two modes to be translational and the third librational in accordance with previous assignments. The Gruneisen parameter of the libration is lower than expected for purely octopolar electrostatic interactions between molecules. The change in frequency with temperature of all three modes is due to their interaction with the mode near 108 cm^-1. The lifetimes of both translations are determined by their rate of combination with librations near 306 cm^-1 and 313 cm^-1. The lifetime of the libration near 306 cm^-1 depends on its rate of combination with the two translations (108 cm^-1 and 140 cm^-1) and a libration near 440 cm^-1.
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Date Issued
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1985
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PURL
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http://purl.flvc.org/fcla/dt/14251
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Subject Headings
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Ammonia--Analysis, Ammonia--Spectra, Lattice dynamics, Raman spectroscopy
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Format
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Document (PDF)
