Effect of transformation twins on the anelastic behavior of polycrystalline Ca1-xSrxTiO3 and SrxBa1-xSnO3 perovskite in relation to the seismic properties of Earths mantle perovskite

Daraktchiev, M. and Harrison, R. J. and Mountstevens, E. H. and Redfern, S. A. T. (2006) Effect of transformation twins on the anelastic behavior of polycrystalline Ca1-xSrxTiO3 and SrxBa1-xSnO3 perovskite in relation to the seismic properties of Earths mantle perovskite. Materials Science and Engineering A, 442 (1-2). pp. 199-203. ISSN 0921-5093 DOI 10.1016/j.msea.2006.01.141

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Abstract

The mechanical loss of Ca1−xSrxTiO3 as a function of temperature has been studied up to 1000 ◦C using dynamical mechanical analysis. The loss spectrum reveals a relaxation peak in the tetragonal phase and negligible mechanical loss in the cubic and orthorhombic phases. The peak is accompanied by a softening of the storage modulus, caused by the formation of mobile transformation twin domain walls. The small value of internal friction in the orthorhombic phase is associated with a negative volume strain, resulting in domain walls that are strongly pinned by lattice defects. The volume changes and mechanical loss in Ca1−xSrxTiO3 are compared with those in SrxBa1−xSnO3, a system which shows a positive volume strain. In contrast to Ca1−xSrxTiO3, SrxBa1−xSnO3 displays a thermally activated peak in the orthorhombic phase. A frequency-independent peak attributed to the tetragonal–orthorhombic transition is also seen. The positive volume strain in SrxBa1−xSnO3 results in domain wall structures that are less strongly pinned by lattice defects.

Item Type: Article
Uncontrolled Keywords: 2006 AREP IA52 2006 P
Subjects: 03 - Mineral Sciences
Divisions: 03 - Mineral Sciences
Journal or Publication Title: Materials Science and Engineering A
Volume: 442
Page Range: pp. 199-203
Identification Number: 10.1016/j.msea.2006.01.141
Depositing User: Sarah Humbert
Date Deposited: 16 Feb 2009 13:02
Last Modified: 23 Jul 2013 10:06
URI: http://eprints.esc.cam.ac.uk/id/eprint/233

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