Key role of polar nanoregions in the cubic-to-tetragonal phase transition of potassium-based perovskites
Year: 2022
Authors: Parravicini J., Delre E., Perego S., Acciarri M., Binetti S., Garcia Y., Parapelitsa G., Agranat AJ., Parravicini G.
Autors Affiliation: Univ Firenze, Dipartimento Fis & Astron, I-50019 Sesto Fiorentino, Italy; Univ Firenze, European Lab Nonlinear Spect, LENS, I-50019 Sesto Fiorentino, Italy; CNR INO, I-50019 Sesto Fiorentino, Italy; Sapienza Univ Roma, Dipartimento Fis, I-00185 Rome, Italy; Univ Milano Bicocca, Dipartimento Sci Mat, I-20125 Milan, Italy; Hebrew Univ Jerusalem, Appl Phys Dept, IL-91904 Jerusalem, Israel; Univ Pavia, Dipartimento Fis, I-27100 Pavia, Italy.
Abstract: We investigate samples of compositionally disordered potassium-based perovskite single crystals with different composition and stoichiometry. The dielectric and Raman response is inspected over the nominal cubic-to-tetragonal long-range phase transition. The comparison between results shows that the occurrence of the phase transition is controlled by the temperature evolution of polar nanoregions (PNRs). We are able to correlate PNR order, formation, percolation, and freezing to the characteristic temperatures of each macroscopic crystal. The onset of the phase transition is found to occur when PNRs undergo a percolative ordering process, in correlation to the sudden arising of a specific high-frequency Raman mode.
Journal/Review: PHYSICAL REVIEW B
Volume: 106 (6) Pages from: 64107-1 to: 64107-13
KeyWords: Scale-free Optics; Kta1-xnbxo3 Single-crystals; Diffraction Cancellation; Raman-scattering; DynamicsDOI: 10.1103/PhysRevB.106.064107ImpactFactor: 3.700Citations: 4data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2024-09-15References taken from IsiWeb of Knowledge: (subscribers only)
