Experimental and theoretical study of the vibrational properties of diaspore (α-AlOOH)

Delattre, Simon and Balan, Etienne and Lazzeri, Michele and Blanchard, Marc and Guillaumet, Maxime and Beyssac, Olivier and Haussühl, Eiken and Winkler, Björn and Salje, Ekhard K. H. and Calas, Georges (2011) Experimental and theoretical study of the vibrational properties of diaspore (α-AlOOH). Physics and Chemistry of Minerals, 39 (2). pp. 93-102. ISSN 0342-1791 (Print) 1432-2021 (Online) DOI 10.1088/0953-8984/23/10/105402

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Abstract

Vibrational properties of diaspore, α-AlOOH, have been re-investigated using room-temperature single-crystal Raman spectroscopy and low-temperature powder infrared (IR) transmission spectroscopy. First-principles harmonic calculations based on density functional theory provide a convincing assignment of the major Raman peaks and infrared absorption bands. The large width of the Raman band related to OH stretching modes is ascribed to mode–mode anharmonic coupling due to medium-strength H-bonding. Additional broadening in the powder IR spectrum arises from depolarization effects in powder particles. The temperature dependence of the IR spectrum provides a further insight into the anharmonic properties of diaspore. Based on their frequency and temperature behavior, narrow absorption features at ~2,000 cm−1 and anti-resonance at ~2,966 cm−1 in the IR spectrum are interpreted as overtones of fundamental bending bands.

Item Type:	Article
Uncontrolled Keywords:	2011AREP; IA63;
Subjects:	03 - Mineral Sciences
Divisions:	03 - Mineral Sciences
Journal or Publication Title:	Physics and Chemistry of Minerals
Volume:	39
Page Range:	pp. 93-102
Identification Number:	10.1088/0953-8984/23/10/105402
Depositing User:	Sarah Humbert
Date Deposited:	08 Feb 2012 10:11
Last Modified:	23 Jul 2013 10:03
URI:	http://eprints.esc.cam.ac.uk/id/eprint/2373

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