Nanometer structure as a key to various phenomena in ferroelectrics

Abstract

The results of studying ferroelectric materials obtained at the Institute of Automation and Electrometry of the Siberian Branch of the Russian Academy of Sciences in 1973-2020 are reported. Mechanisms of the photovoltaic effect and photorefraction, emergence and role of polar regions in ferroelectric crystals, methods of detection of polar regions, and mechanisms of manifestation of the displacive and order-disorder phase transitions in various ferroelectrics are discussed. The results of experimental and theoretical investigations allow one to conclude that imperfections of a crystal structure play a key role in phenomena observed in ferroelectrics.

Keywords:

• Ferroelectric crystals
• local polar regions
• ferroelectric phase transition
• Raman spectroscopy
• Brillouin spectroscopy

Acknowledgements

Some part of the experiments was performed in the multiple-access center “High-Resolution Spectroscopy of Gases and Condensed Matter” in IA&E SBRAS (Novosibirsk, Russia).

Additional information

Funding

This work was supported by the Russian Foundation for Basic Research, projects no. 18-02-00399 and 19-42-543-016, Government of Novosibirsk region No. 19-42-543-016, and State assignment No AAAA-A17-117052410033-9.