Phases in the (1-x)Na0.5Bi0.5TiO3-(x)CaTiO3 system

Ranjan, Rajeev and Garg, Rohini and Kothai, V and Agrawal, Anupriya and Senyshyn, Anatoliy and Boysen, Hans (2010) Phases in the (1-x)Na0.5Bi0.5TiO3-(x)CaTiO3 system. In: Journal of Physics: Condensed Matter, 22 (7).

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Abstract

The structures of (1 - x) Na0.5Bi0.5TiO3-(x) CaTiO3 at room temperature have been investigated using neutron powder diffraction and dielectric studies. The system exhibits an orthorhombic (Pbnm) structure for x >= 0.15 and rhombohedral (R3c) for x <= 0.05. For x = 0.10, though the neutron diffraction pattern shows features of the orthorhombic (Pbnm) structure, Rietveld refinement using this structure shows a drastic reduction in the in-phase tilt angle (similar to 4 degrees) as compared to the corresponding value (similar to 8 degrees) for a neighbouring composition x = 0.15. The neutron diffraction pattern of x = 0.10 could be fitted equally well using a two-phase model (R3c + Pbnm) with orthorhombic as the minor phase (22%), without the need for a drastic decrease in the in-phase tilt angle. The dielectric studies of x = 0.10 revealed the presence of the polar R3c phase, thereby favouring the phase coexistence model, instead of a single-phase Pbnm structure, for this composition.

Item Type:	Journal Article
Publication:	Journal of Physics: Condensed Matter
Publisher:	Institute of Physics
Additional Information:	Copyright of this article belongs to Institute of Physics.
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	08 Mar 2010 13:52
Last Modified:	19 Sep 2010 05:55
URI:	http://eprints.iisc.ac.in/id/eprint/25791

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