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Title: Electronic and atomic structure of Mn-doped CaF sub 2 : An x-ray-absorption near-edge structure and extended x-ray-absorption fine-structure study

Abstract

X-ray-absorption near-edge structure (XANES) and extended-x-ray-absorption fine-structure (EXAFS) measurements have been performed on the calcium {ital K} edge and manganese {ital K} edge of CaF{sub 2} doped with manganese at molecular concentrations of 0.1--2.5 %. The results are compared to other measurements of the calcium {ital K} edge in CaF{sub 2} and the Mn {ital K} edge in various manganese compounds. Major features in the XANES spectra are tentatively identified with transitions to high-symmetry points of the CaF{sub 2} energy bands in a one-electron picture. Expected deviations from the structure predicted by the one-electron formalism are discussed. The EXAFS analysis shows a reduction in the manganese-fluorine distance of (3.9{plus minus}0.4)% as compared to the calcium-fluorine separation in the doped or undoped samples. This compares well with previous results obtained by EPR. A significant increase in disorder of the first shell around the Mn dopant ion is observed as compared to the Ca ion. The significance of this shell contraction and disorder is discussed in terms of possible defect structures in the material.

Authors:
;  [1]
  1. Naval Surface Warfare Center, Research and Technology Department, Silver Spring, Maryland 20903 (United States)
Publication Date:
OSTI Identifier:
7038404
DOE Contract Number:  
AS05-80ER10742; AC02-76CH00016
Resource Type:
Journal Article
Journal Name:
Physical Review, B: Condensed Matter; (United States)
Additional Journal Information:
Journal Volume: 46:14; Journal ID: ISSN 0163-1829
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CALCIUM FLUORIDES; ELECTRONIC STRUCTURE; ABSORPTION SPECTRA; MANGANESE ADDITIONS; X RADIATION; ALKALINE EARTH METAL COMPOUNDS; ALLOYS; CALCIUM COMPOUNDS; CALCIUM HALIDES; ELECTROMAGNETIC RADIATION; FLUORIDES; FLUORINE COMPOUNDS; HALIDES; HALOGEN COMPOUNDS; IONIZING RADIATIONS; MANGANESE ALLOYS; RADIATIONS; SPECTRA; 360602* - Other Materials- Structure & Phase Studies; 360606 - Other Materials- Physical Properties- (1992-)

Citation Formats

Barkyoumb, J H, and Mansour, A N. Electronic and atomic structure of Mn-doped CaF sub 2 : An x-ray-absorption near-edge structure and extended x-ray-absorption fine-structure study. United States: N. p., 1992. Web. doi:10.1103/PhysRevB.46.8768.
Barkyoumb, J H, & Mansour, A N. Electronic and atomic structure of Mn-doped CaF sub 2 : An x-ray-absorption near-edge structure and extended x-ray-absorption fine-structure study. United States. https://doi.org/10.1103/PhysRevB.46.8768
Barkyoumb, J H, and Mansour, A N. Thu . "Electronic and atomic structure of Mn-doped CaF sub 2 : An x-ray-absorption near-edge structure and extended x-ray-absorption fine-structure study". United States. https://doi.org/10.1103/PhysRevB.46.8768.
@article{osti_7038404,
title = {Electronic and atomic structure of Mn-doped CaF sub 2 : An x-ray-absorption near-edge structure and extended x-ray-absorption fine-structure study},
author = {Barkyoumb, J H and Mansour, A N},
abstractNote = {X-ray-absorption near-edge structure (XANES) and extended-x-ray-absorption fine-structure (EXAFS) measurements have been performed on the calcium {ital K} edge and manganese {ital K} edge of CaF{sub 2} doped with manganese at molecular concentrations of 0.1--2.5 %. The results are compared to other measurements of the calcium {ital K} edge in CaF{sub 2} and the Mn {ital K} edge in various manganese compounds. Major features in the XANES spectra are tentatively identified with transitions to high-symmetry points of the CaF{sub 2} energy bands in a one-electron picture. Expected deviations from the structure predicted by the one-electron formalism are discussed. The EXAFS analysis shows a reduction in the manganese-fluorine distance of (3.9{plus minus}0.4)% as compared to the calcium-fluorine separation in the doped or undoped samples. This compares well with previous results obtained by EPR. A significant increase in disorder of the first shell around the Mn dopant ion is observed as compared to the Ca ion. The significance of this shell contraction and disorder is discussed in terms of possible defect structures in the material.},
doi = {10.1103/PhysRevB.46.8768},
url = {https://www.osti.gov/biblio/7038404}, journal = {Physical Review, B: Condensed Matter; (United States)},
issn = {0163-1829},
number = ,
volume = 46:14,
place = {United States},
year = {1992},
month = {10}
}