Title

On thermal and vibrational properties of LaGaO3 single crystals

Authors

Authors

N. Orlovskaya; M. Lugovy; C. Carpenter; S. Pathak; D. Steinmetz; E. Lara-Curzio; C. Klemenz;M. Radovic

Comments

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Abbreviated Journal Title

Acta Mater.

Keywords

Perovskite; Phase transition; Thermal expansion; Raman spectroscopy; X-RAY-DIFFRACTION; NEUTRON POWDER DIFFRACTION; PHASE-TRANSITION; LANTHANUM GALLATE; ORTHORHOMBIC LAGAO3; SOLID-ELECTROLYTE; SODIUM; NIOBATE; PEROVSKITE; PRESSURE; RAMAN; Materials Science, Multidisciplinary; Metallurgy & Metallurgical; Engineering

Abstract

The thermal expansion and vibrational properties of [100] and [001]LaGaO3 single crystals have been studied by thermal mechanical analysis and micro-Raman spectroscopy. A first-order orthorhombic to rhombohedral phase transition has been confirmed by both techniques, as well as by in situ heating using optical microscopy. The appearance of a metastable intermediate phase, tentatively assigned as monoclinic, has been detected both by optical microscopy and Raman spectroscopy upon heating of the [100] and [001] LaGaO3 single crystals. Not only temperature, but the stress-induced orthorhombic to rhombohedral phase transition has also been detected by Raman mapping of the residual impression made by Vickers indentation. The position map of bands belonging to the lower-temperature/pressure orthorhombic and the higher-temperature/pressure rhombohedral phase show that the rhombohedral phase is located inside the impression, where the applied indentation stresses are the highest, whereas no rhombohedral phase is detected Outside the impression, where the Surface has not been altered by contact stresses. (C) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Journal Title

Acta Materialia

Volume

57

Issue/Number

10

Publication Date

1-1-2009

Document Type

Article

Language

English

First Page

2984

Last Page

2992

WOS Identifier

WOS:000266518600011

ISSN

1359-6454

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