Effect of an Eu{sup 3+} impurity on the antiferrodistortion and ferroelectric instabilities in an EuTiO{sub 3} bulk crystal and thin films

Journal Article · Thu Jan 15 04:00:00 EST 2015 · Journal of Experimental and Theoretical Physics

DOI:https://doi.org/10.1134/S1063776115010070· OSTI ID:22472433

Zamkova, N. G.; Zinenko, V. I. ^[1]

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1. Russian Academy of Sciences, Kirensky Institute of Physics, Siberian Branch (Russian Federation)

The existence of an antiferrodistortion transition in EuTiO{sub 3} is disputable, and this question needs to be answered. One of the possible causes is the presence of an Eu{sup 3+} impurity in a sample. A nonempirical polarizable ion model is used to study the effect of a trivalent Eu{sup 3+} ion impurity on the antiferrodistortion and ferroelectric instabilities of an EuTiO{sub 3} crystal in the bulk and the thin-film states. Lattice dynamics calculation shows that a bulk impurity-free EuTiO{sub 3} crystal has no unstable modes throughout the entire phase space volume. The addition of an Eu{sup 3+} impurity leads to a significant softening of the rotational mode, the distortion in which makes tetragonal phase I4/mcm (which is experimentally observed) energetically favorable. In going from the bulk crystal to the thin film, the vibration spectrum of the impurity-free film has unstable antiferrodistortion and rotational modes. The addition of an Eu{sup 3+} impurity enhances the antiferrodistortion instability, which fully or partly suppresses ferroelectricity.

• OSTI ID: 22472433
• Journal Information: Journal of Experimental and Theoretical Physics, Journal Name: Journal of Experimental and Theoretical Physics Journal Issue: 1 Vol. 120; ISSN JTPHES; ISSN 1063-7761
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CRYSTALS
EUROPIUM COMPOUNDS
EUROPIUM IONS
FERROELECTRIC MATERIALS
IMPURITIES
PHASE SPACE
TETRAGONAL LATTICES
THIN FILMS
TITANATES