Large structural heterogeneity in submicrometer BaTiO3revealed via Eu+3photoluminescence study

De, A and Ranjan, R (2020) Large structural heterogeneity in submicrometer BaTiO3revealed via Eu+3photoluminescence study. In: Journal of Applied Physics, 128 (12).

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Abstract

Apart from being a model ferroelectric, BaTiO3 and its derivatives are materials of considerable technological importance in the capacitor industry and as a potential Pb-free piezoelectric. Here, we have examined BaTiO3 for its propensity to stabilize local low symmetry distortions and induce structural heterogeneity for two different situations, namely, (1) by introducing inhomogeneous lattice strain and (2) by restricting the average grain size to the submicrometer regime. We have introduced Eu+3 ions in BaTiO3 in a very dilute concentration to act as local probes. Our strategy relies on exploiting the great sensitivity of the 5D0 → 7F2 transition of Eu+3 with regard to the variation in the asymmetric distribution of the ligand field around itself to probe the structural heterogeneity developed in BaTiO3. The Eu+3 photoluminescence signal revealed a remarkable increase in the local structural heterogeneity in submicrometer (∼0.4 μm) sized BaTiO3. This manifests as an ∼170% increase in the intensity of the 7F2 band with respect to the structure insensitive 7F1 band. Although to a lesser extent, a similar scenario was observed when the large grain BaTiO3 develops residual strain. The structural insights presented here can be helpful in explaining the properties of BaTiO3-based multilayered ceramics wherein the two conditions of submicrometer size and residual strain is a common occurrence.

Item Type:	Journal Article
Publication:	Journal of Applied Physics
Publisher:	American Institute of Physics Inc.
Additional Information:	The copyright for this article belongs to American Institute of Physics Inc.
Keywords:	Barium titanate; Ferroelectric materials; Lead compounds; Photoluminescence; Sensitivity analysis, Asymmetric distribution; Average grain size; Dilute concentrations; Lattice strain; Photoluminescence signals; Residual strains; Structural heterogeneity; Structural insights, Europium compounds
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	13 Feb 2023 10:33
Last Modified:	13 Feb 2023 10:33
URI:	https://eprints.iisc.ac.in/id/eprint/80218

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