The chromium site in doped glassy lithium tetraborate

Authors

T D. Kelly, Air Force Institute of Technology
E Echeverria, University of Nebraska-LincolnFollow
Sumit Beniwal, University of Nebraska-LincolnFollow
V T. Adamiv, Institute of Physical Optics
Ya V. Burak, Institute of Physical Optics
Axel Enders, Institute of Physical OpticsFollow
J. C. Petrosky, Air Force Institute of TechnologyFollow
J W. McClory, Air Force Institute of Technology
Peter A. Dowben, University of Nebraska-LincolnFollow

Date of this Version

2014

Citation

Materials Chemistry and Physics 147 (2014)

Comments

U.S. Government work

Abstract

Using extended X-ray absorption fine structure (EXAFS) spectroscopy, we find that Cr substitutes primarily in the Liþ site as a dopant in lithium tetraborate Li₂B₄O₇ glasses, in this case 98.4Li₂B₄O₇e_1.6Cr₂O₃ or nominally Li_1.98Cr_0.025B₄O₇. This strong preference for a single site is nonetheless accompanied by site distortions and some site disorder, helping explain the optical properties of chromium doped Li₂B₄O₇ glasses. The resulting O coordination shell has a contraction of the Cr-O bond lengths as compared to the Li-O bond lengths. There is also an increase in the O coordination number.