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X‐ray absorption spectroscopy and density functional analysis of the Fe 3+ distribution profile on Al sites in a chrysoberyl crystal, BeAl 2 O 4 :Fe 3+
Author(s) -
Kanchiang Kanokwan,
Bootchat Atipong,
Witthayarat Janyaporn,
Pramchu Sittichain,
Thanasuthipitak Panjawan,
Yimnirun Rattikorn
Publication year - 2016
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s160057671600042x
Subject(s) - xanes , x ray absorption spectroscopy , chemistry , density functional theory , crystallography , absorption spectroscopy , spectroscopy , extended x ray absorption fine structure , absorption (acoustics) , crystal structure , octahedron , analytical chemistry (journal) , computational chemistry , physics , optics , chromatography , quantum mechanics
Chrysoberyl is one of the most interesting minerals for laser applications, widely used for medical purposes, as it exhibits higher laser performance than other materials. Although its utilization has been vastly expanded, the location of transition metal impurities, especially the iron that is responsible for chrysoberyl's special optical properties, is not completely understood. The full understanding and control of these optical properties necessitates knowledge of the precise location of the transition metals inside the structure. Therefore, synchrotron X‐ray absorption spectroscopy (XAS), a local structural probe sensitive to the different local geometries, was employed in this work to determine the site occupation of the Fe 3+ cation in the chrysoberyl structure. An Fe K ‐edge X‐ray absorption near‐edge structure (XANES) simulation was performed in combination with density functional theory calculations of Fe 3+ cations located at different locations in the chrysoberyl structure. The simulated spectra were then qualitatively compared with the measured XANES features. The comparison indicates that Fe 3+ is substituted on the two different Al 2+ octahedral sites with the proportion 60% on the inversion site and 40% on the reflection site. The accurate site distribution of Fe 3+ obtained from this work provides useful information on the doping process for improving the efficiency of chrysoberyl as a solid‐state laser material.