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The effect of thermal vibrations on extended x-ray absorption fine structure. II

Boland, John J. and Baldeschwieler, John D. (1984) The effect of thermal vibrations on extended x-ray absorption fine structure. II. Journal of Chemical Physics, 81 (3). pp. 1145-1159. ISSN 0021-9606. http://resolver.caltech.edu/CaltechAUTHORS:20120629-130908919

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Abstract

A formalism is introduced to describe the dependence of the EXAFS amplitude and phase on thermally excited vibrations. The EXAFS expression for a general three‐atom system of C_s symmetry is discussed in detail. To lowest order, thermal vibrations induce a change only in the scattering path length and give rise to the standard EXAFS expression for each scattering path damped by the appropriate Debye‐Waller factor. A change in scattering angle, however, is a higher order effect and gives rise to additional EXAFS terms called modification factors. There is a modification factor associated with each multiple scattering path. Within this formalism, the correlation which exists between a change in scattering path length and a change in scattering angle is explicitly calculated. The normal modes which contribute to the modification factors are discussed, and shown to be dependent on the symmetry of the system. The nature and temperature dependence of the Debye–Waller and modification factors for the three‐atom system Br_2O are discussed as a function of bridging angle. The modification factors are shown to make a small contribution to the total EXAFS of the system. The magnitude of this contribution is dependent on the degree of correlation that exists between changes in scattering path length and scattering angle.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1063/1.447807DOIUNSPECIFIED
http://jcp.aip.org/resource/1/jcpsa6/v81/i3/p1145_s1PublisherUNSPECIFIED
Additional Information:© 1984 American Institute of Physics. Received 8 September 1983; accepted 12 April 1984. The authors wish to thank Dr. Folim G. Halaka for advice and many helpful discussions, and the National Science Foundation (Grant No. CHE12589). This is contribution No. 6999 from the Arthur Amos Noyes Laboratory of the Department of Chemistry, California Institute of Technology, Pasadena, California 91125.
Funders:
Funding AgencyGrant Number
NSFCHE12589
Subject Keywords:BROMINE OXIDES, DEBYE−WALLER FACTOR, TEMPERATURE DEPENDENCE, LATTICE VIBRATIONS, EXAFS, AMPLITUDES
Other Numbering System:
Other Numbering System NameOther Numbering System ID
Caltech Arthur Amos Noyes Laboratory 6999
Classification Code:PACS: 68.37.-d, 78.70.Dm, 34.80.Bm
Record Number:CaltechAUTHORS:20120629-130908919
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20120629-130908919
Official Citation:The effect of thermal vibrations on extended x‐ray absorption fine structure. II John J. Boland and John D. Baldeschwieler J. Chem. Phys. 81, 1145 (1984); http://dx.doi.org/10.1063/1.447807
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:32208
Collection:CaltechAUTHORS
Deposited By: Ruth Sustaita
Deposited On:02 Jul 2012 15:02
Last Modified:26 Dec 2012 15:26

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