Potassium-based perovskites: The key role of polar nanoregions in their cubic-to-tetragonal phase transition
Year: 2025
Authors: Parravicini J., Delre E., Perego S., Acciarri M., Binetti S., Garcia Y., Perepelitsa G., Agranat A.J., Parravicini G.B.
Autors Affiliation: Univ Firenze, Dipartimento Fis & Astron, CNR INO, I-50019 Sesto Fiorentino, Italy; Univ Firenze, LENS, CNR INO, I-50019 Sesto Fiorentino, Italy; Sapienza Univ Roma, Dipartimento Fis, I-00185 Rome, Italy; Univ Milano Bicocca, Dipartimento Sci Materiali, I-20125 Milan, Italy; Hebrew Univ Jerusalem, Inst Appl Phys, IL-91904 Jerusalem, Israel; Univ Pavia, Dipartimento Fis, I-27100 Pavia, Italy.
Abstract: An experimental study on different samples of disordered potassium-based perovskite compounds, a class of single crystals hosting polar nanoregions (PNRs), is carried out. By combining Raman spectroscopy, dielectric response, and Frohlich entropy estimation, we investigate the specific behavior straddling the nominal cubic-to-tetragonal long-range phase transition. Our results demonstrate that the arising of the phase transition is driven by the temperature evolution of the PNRs, whose behavior is correlated to several macroscopic features. In particular, the onset of the phase transition occurs when PNRs display a percolation process, which is highlighted by the sudden arising of a specific Raman mode.
Journal/Review: Nuovo Cimento C-Colloquia and Communications in Physics
Volume: 48 (4) Pages from: 208-1 to: 208-4
More Information: This research was supported in part by the state of Israel, Ministry of Science, Technology and Innovation Grant No. 4698.DOI: 10.1393/ncc/i2025-25208-9
