We perform redundant X-ray diraction versus temperature experiments in bulk transparent KTN. We nd a violation of the standard perovskite cubic-to-tetragonal symmetry-breaking at the Curie point in the form of an orthorhombic cell distortion. The lattice distortion spans coherently macroscopic volumes of the sample and is characterized by a negative-to-zero thermal volumeexpansion. Dielectric measurements and calorimetry indicate that the anomalous behavior is not associated to a distinct thermodynamic phase. The comparison of linear and nonlinear optical scattering experiments with structural data suggests that the lattice distortion is a consequence of strain relaxation to a 3D superlattice of polarization vortices.

Lo Presti, L., Parravicini, J., Soave, R., Parravicini, G., Mauri, M., Loconte, L., et al. (2020). Observation of an exotic lattice structure in the transparent KTa1-xNbx O3 perovskite supercrystal. PHYSICAL REVIEW. B, 102(21) [10.1103/PhysRevB.102.214110].

Observation of an exotic lattice structure in the transparent KTa1-xNbx O3 perovskite supercrystal

J. Parravicini
Secondo
;
M. Mauri;S. Binetti;
2020

Abstract

We perform redundant X-ray diraction versus temperature experiments in bulk transparent KTN. We nd a violation of the standard perovskite cubic-to-tetragonal symmetry-breaking at the Curie point in the form of an orthorhombic cell distortion. The lattice distortion spans coherently macroscopic volumes of the sample and is characterized by a negative-to-zero thermal volumeexpansion. Dielectric measurements and calorimetry indicate that the anomalous behavior is not associated to a distinct thermodynamic phase. The comparison of linear and nonlinear optical scattering experiments with structural data suggests that the lattice distortion is a consequence of strain relaxation to a 3D superlattice of polarization vortices.
Articolo in rivista - Articolo scientifico
perovskite; disorder; X-ray; Ferroelectricity; Phase transitions; Structural properties; Complex Materials; Crystal structures
English
17-dic-2020
2020
102
21
214110
none
Lo Presti, L., Parravicini, J., Soave, R., Parravicini, G., Mauri, M., Loconte, L., et al. (2020). Observation of an exotic lattice structure in the transparent KTa1-xNbx O3 perovskite supercrystal. PHYSICAL REVIEW. B, 102(21) [10.1103/PhysRevB.102.214110].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/296113
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