Unusual dielectric response in B-site size-disordered hexagonal transition metal oxides

Choudhury, Debraj and Venimadhav, Adyam and Kakarla, Chandrasekhar and Delaney, Kris T and Devi, Sujatha P and Mondal, P and Nirmala, R and Gopalakrishnan, J and Spaldin, Nicola A and Waghmare, Umesh V and Sarma, DD (2010) Unusual dielectric response in B-site size-disordered hexagonal transition metal oxides. In: Applied Physics Letters, 96 (16).

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Abstract

We discover that hexagonal holmium copper titanate (Ho2CuTiO6), has a unique and highly desirable combination of high dielectric constant, low losses, very small temperature coefficient, and low frequency dependence. Our first-principles calculations indicate that these exceptional properties result from a size-difference at the Cu/Ti B-site that suppresses the expected ferroelectric transition, combined with the dominance of intermediate-frequency polar vibrational modes in the dielectric response. Our results suggest that the use of such B-site disorder in alloys of hexagonal transition-metal oxides should generally result in similar robust dielectrics.

Item Type:	Journal Article
Publication:	Applied Physics Letters
Publisher:	American Institute of Physics
Additional Information:	Copyright of this article belongs to American Institute of Physics.
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit Division of Physical & Mathematical Sciences > Physics
Date Deposited:	04 Jun 2010 05:09
Last Modified:	19 Sep 2010 06:06
URI:	http://eprints.iisc.ac.in/id/eprint/27720

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