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Title: Structure and vibrational dynamics of isotopically labeled lithium borohydride using neutron diffraction and spectroscopy

Abstract

The crystalline structure of a {sup 7}Li and {sup 11}B labeled lithium borohydride has been investigated using neutron powder diffraction at 3.5, 360, and 400 K. The B-H bond lengths and H-B-H angles for the [BH{sub 4}]{sup -} tetrahedra indicated that the tetrahedra maintained a nearly ideal configuration throughout the temperature range investigated. The atomic displacement parameters at 360 K suggest that the [BH{sub 4}]{sup -} tetrahedra become increasingly disordered as a result of large amplitude librational and reorientational motions as the orthorhombic to hexagonal phase transition (T=384 K) is approached. In the high-temperature hexagonal phase, the [BH{sub 4}]{sup -} tetrahedra displayed extreme disorder about the trigonal axis along which they are aligned. Neutron vibrational spectroscopy data were collected at 5 K over an energy range of 10-170 meV, and were found to be in good agreement with prior Raman and low-resolution neutron spectroscopy studies. - Graphical abstract: The structure of {sup 7}Li{sup 11}BH{sub 4} in the low-temperature Pnma phase, including atomic displacement ellipsoids, at 3.5 K.

Authors:
 [1];  [2];  [2];  [3];  [4]
  1. NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899-8562 (United States), E-mail: mike.hartman@oregonstate.edu
  2. NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899-8562 (United States)
  3. Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)
  4. Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125 (United States)
Publication Date:
OSTI Identifier:
21015777
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 180; Journal Issue: 4; Other Information: DOI: 10.1016/j.jssc.2007.01.031; PII: S0022-4596(07)00073-4; Copyright (c) 2007 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ATOMIC DISPLACEMENTS; BOND LENGTHS; BOROHYDRIDES; BORON HYDRIDES; CRYSTAL-PHASE TRANSFORMATIONS; HEXAGONAL LATTICES; HYDROGEN STORAGE; LITHIUM COMPOUNDS; MEV RANGE 01-10; MEV RANGE 10-100; MEV RANGE 100-1000; NEUTRON DIFFRACTION; NEUTRON SPECTROSCOPY; NUCLEAR MAGNETIC RESONANCE; ORTHORHOMBIC LATTICES; TEMPERATURE RANGE 0000-0013 K; TEMPERATURE RANGE 0273-0400 K; TEMPERATURE RANGE 0400-1000 K

Citation Formats

Hartman, Michael R., Rush, John J., Udovic, Terrence J., Bowman, Robert C., and Hwang, Son-Jong. Structure and vibrational dynamics of isotopically labeled lithium borohydride using neutron diffraction and spectroscopy. United States: N. p., 2007. Web. doi:10.1016/j.jssc.2007.01.031.
Hartman, Michael R., Rush, John J., Udovic, Terrence J., Bowman, Robert C., & Hwang, Son-Jong. Structure and vibrational dynamics of isotopically labeled lithium borohydride using neutron diffraction and spectroscopy. United States. doi:10.1016/j.jssc.2007.01.031.
Hartman, Michael R., Rush, John J., Udovic, Terrence J., Bowman, Robert C., and Hwang, Son-Jong. Sun . "Structure and vibrational dynamics of isotopically labeled lithium borohydride using neutron diffraction and spectroscopy". United States. doi:10.1016/j.jssc.2007.01.031.
@article{osti_21015777,
title = {Structure and vibrational dynamics of isotopically labeled lithium borohydride using neutron diffraction and spectroscopy},
author = {Hartman, Michael R. and Rush, John J. and Udovic, Terrence J. and Bowman, Robert C. and Hwang, Son-Jong},
abstractNote = {The crystalline structure of a {sup 7}Li and {sup 11}B labeled lithium borohydride has been investigated using neutron powder diffraction at 3.5, 360, and 400 K. The B-H bond lengths and H-B-H angles for the [BH{sub 4}]{sup -} tetrahedra indicated that the tetrahedra maintained a nearly ideal configuration throughout the temperature range investigated. The atomic displacement parameters at 360 K suggest that the [BH{sub 4}]{sup -} tetrahedra become increasingly disordered as a result of large amplitude librational and reorientational motions as the orthorhombic to hexagonal phase transition (T=384 K) is approached. In the high-temperature hexagonal phase, the [BH{sub 4}]{sup -} tetrahedra displayed extreme disorder about the trigonal axis along which they are aligned. Neutron vibrational spectroscopy data were collected at 5 K over an energy range of 10-170 meV, and were found to be in good agreement with prior Raman and low-resolution neutron spectroscopy studies. - Graphical abstract: The structure of {sup 7}Li{sup 11}BH{sub 4} in the low-temperature Pnma phase, including atomic displacement ellipsoids, at 3.5 K.},
doi = {10.1016/j.jssc.2007.01.031},
journal = {Journal of Solid State Chemistry},
number = 4,
volume = 180,
place = {United States},
year = {Sun Apr 15 00:00:00 EDT 2007},
month = {Sun Apr 15 00:00:00 EDT 2007}
}
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