On thermal and vibrational properties of LaGaO3 single crystals

    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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