Accession Number : AD0275979

Title :   THE TEMPERATURE DEPENDENCE OF THE EXTENDED X-RAY ABSORPTION FINE STRUCTURE

Corporate Author : BOEING SCIENTIFIC RESEARCH LABS SEATTLE WASH

Personal Author(s) : LYTLE,FARREL W.

Report Date : APR 1962

Pagination or Media Count : 1

Abstract : A theory of x-ray absorption fine structure was first proposed by Kronig. In his derivation the photoelectron ejected in the x-ray absorption process moves through the crystal as a free electron. By assuming that the o ly influence upon the electron is a small perturbation due to the periodic field of the la tice, it is found that certain energy regions occur which are forbidden to the electron; a forbidden energy region is that combination of momentum and direction for which the Bragg diffraction condition is fulfilled (Brillouin zone boundary). This inv stigation was to determine the effect of temperatures in the range fro li uid helium to room temperature upon extended x-ray absorption fine structure. If the effect could be shown compatible with a diffraction mechanism, then t e basic fea ur of t Kronig theory must be valid. (Author)

Descriptors :   *DIFFRACTION, *HYPERFINE STRUCTURE, *TEMPERATURE, *X RAYS, ABSORPTION, BRILLOUIN ZONES, COPPER, CRYOSTATS, CRYSTAL LATTICES, CRYSTAL STRUCTURE, ELECTRONS, MEASUREMENT, NICKEL, PHOTOELECTRONS, SINGLE CRYSTALS, X RAY DIFFRACTION, X RAY SPECTROSCOPY

Distribution Statement : APPROVED FOR PUBLIC RELEASE