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