Registration Number
0225U004367,
(0124U004302)
, R & D reports
Title
Layered ferroics MM'P₂S(Se)₆ with unique functional properties for nanoscale heterostructures.
popup.stage_title
Вивчення синергії термічно активованих катіонів міді чи срібла і ангармонічної динаміки катіонів індію або вісмуту у спонтанному дипольному впорядкуванні та у контрольованій імпульсами електричного поля міграції катіонів через структурні шари кристалів MM'P2S(Se)6.
Head
Vysochanskyi Yulian M., Доктор фізико-математичних наук
Registration Date
02-12-2025
Organization
Uzhhorod National University State Higher Educational Institution
popup.description1
The work involves a combination of technological, experimental and theoretical studies of phosphorus-containing chalcogenide van der Waals single crystals MM'P₂S(Se)₆ (M - Cu, Ag; M' - In, Bi) and heterostructures based on them. The electronic and phonon spectra of crystals, size effects in nanolayers and heterostructures, ferroelectric, semiconducting and thermodynamic properties will be studied. Spontaneous polarization switching kinetics and dielectric properties, ionic conductivity and resistive switching of layered CuInP₂S₆ crystals with chemically modified properties will be studied. The study of the synergy of thermally activated copper or silver cations and the anharmonic dynamics of indium or bismuth cations in the spontaneous dipole ordering and in the cation migration controlled by electric field pulses through the structural layers will facilitate the design of new electronic devices based on the connection between the ferroelectric properties and the ionic conductivity of nanoscale layered packages of CuInP₂S₆ or AgBiP₂Se₆ compounds. The results of the work will be the basis for the creation of functional elements of devices for efficient processing of dynamic information with high density, covering spatial and temporal aspects, which is important for machine vision systems.
popup.description2
The flexoelectric coupling in the ferrielectric crystal CuInP2S6 was analyzed based on the study of the linear interaction between the acoustic and low-frequency optical phonon dispersion branches. The influence of pressure and an electric field on the flexoelectric interaction between spontaneous polarization fluctuations and elastic deformations in CuInP₂S₆ was also studied. The frequency of acoustic phonons was found to decrease to zero at wave vectors near the center of the Brillouin zone, indicating the possibility of an incommensurate phase with spatial modulation of spontaneous polarization. Electric field impulses in a CuInP₂S₆ ferroelectric nanomembrane induce strong coupling between soft optical phonons and acoustic phonons of the resonator. This effect can be applied to develop new quantum systems for computing and sensorics. The results of the study of the interaction between spontaneous polarization fluctuations and elastic deformations in CuInP2S6 can be applied to flexoengineering. Controlling changes in mechanical stress or the chemical composition of CuInP2S6-based solid solutions enables varying the nonlinear coupling between polar and antipolar configurations of electric dipoles, which allows for the implementation of single, double, and triple loops of dielectric hysteresis and multistate switching of spontaneous polarization under external electric field.
Product Description
popup.authors
Medulych Mykola M.
Molnar Oleksandr O.
Pogodin Artem I.
Kohutych Anton A
HLUKhOV Kostiantyn Ye.
YEVYCH Ruslan M.
Vysochanskyi Yulian M.
Liubachko Vitalii Yu.
Hryts Viacheslav Yu.
Shender Iryna O.
popup.nrat_date
2025-12-02
