Observation of an exotic lattice structure in the transparent KTa1-xNbxO3 perovskite supercrystal | |
Article | |
关键词: PHASE-TRANSITIONS; FERROELECTRIC TRANSITIONS; DIFFRACTION CANCELLATION; DIELECTRIC PERMITTIVITY; DOMAIN-STRUCTURES; SINGLE-CRYSTALS; SOLID-SOLUTIONS; SCATTERING; EVOLUTION; DISORDER; | |
DOI : 10.1103/PhysRevB.102.214110 | |
来源: SCIE |
【 摘 要 】
We perform redundant x-ray diffraction versus temperature experiments in bulk transparent KTN. We find 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 volume expansion. 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.
【 授权许可】
Free