Ferroelectric, Ferroelastic and Multiferroic Domain Walls: a New Horizon in Nanoscale Functional Materials
Lead Research Organisation:
University of Cambridge
Department Name: Earth Sciences
Abstract
Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.
Organisations
Publications
Yokota H
(2020)
Direct evidence of polar ferroelastic domain boundaries in semiconductor BiVO4
in Applied Physics Letters
Wang X
(2018)
Glassy behavior and dynamic tweed in defect-free multiferroics
in Applied Physics Letters
He X
(2018)
Immobile defects in ferroelastic walls: Wall nucleation at defect sites
in Applied Physics Letters
Beirau T
(2019)
Avalanches during recrystallization in radiation-damaged pyrochlore and allanite: Statistical similarity to phase transitions in functional materials
in Applied Physics Letters
Xu Y
(2020)
Anisotropic avalanche dynamics during ferroelectric switching in BaTiO3 and 0.7Pb(Mg2/3Nb1/3)O3-0.3PbTiO3
in Applied Physics Letters
Zhang L
(2020)
Statistical analysis of emission, interaction and annihilation of phonons by kink motion in ferroelastic materials
in Applied Physics Letters
Lu G
(2019)
Piezoelectricity and electrostriction in ferroelastic materials with polar twin boundaries and domain junctions
in Applied Physics Letters
Salje E
(2021)
Acoustic Emission Spectroscopy: Applications in Geomaterials and Related Materials
in Applied Sciences
McNulty J
(2020)
Local Structure and Order-Disorder Transitions in "Empty" Ferroelectric Tetragonal Tungsten Bronzes
in Chemistry of Materials
Salje E
(2020)
Polaronic States and Superconductivity in WO3-x
in Condensed Matter
Description | We have identified unique combinations of microstructures in crystals which undergo phase transitions - with a focus on vortices and twin walls in materials including BaTiO3, ferroelectric tungsten bronzes, multiferroic orthorhombic perovskites, pnictide superconductors. This work has expanded greatly in terms of the range of domain wall materials that we have investigated successfully, and in terms of our successful collaborations with other members of the network group. More specifically, domain wall switching and the internal wall structure has been shown to divide into two categories: wild and mild. Wild switching results in highly correlated movements with power law statistics. This means that this switching is scale invariant in time and space and hence allows for high frequency applications in mobile phones etc. Mild switching is thermally activated and dominates in the deformation of wires, bio-mineralisation and some medical applications. Here the choice of the optimal frequency in key and applications rely not only on the amplitude of the switching process but also on the time span and hence the frequency of the pertubation. Ferroelectric switching, such as in BaTiO3, was shown to be history dependent and the nature of the morphotropic boundary in the commonly used material PZT was identified. It consists of highly correlated clusters of ferroelectric domains which act as units rather than splitting into individual domain walls. The same effect was found in cryogenic SrTiO3 near the quantum critical point where all domain movements become fully coherent. These effects dominate the mechanical properties (like the elasticity) of the material and generate piezoelectricity in nominally cubic materials. In theory, we have clarified wall-wall interactions in the bulk and in thin films, the interaction between domain boundaries with surfaces and the role of percolation in domain wall movements. We predicted weak magnetic signals when moving ferroelastic wall even without any magnetic atoms in the bulk. We identified the mixing properties of movements of different origin (like twin walls, dislocations, atomic defect displacements etc) during acoustic emission experiment which enlarges the way such techniques can now be used. |
Exploitation Route | We are expecting that the scientific progress we have made with respect to understanding the structure, dynamics and properties of domain walls will be of significant assistance to the electronics industry involved in the development of new nanoscale devices. Our work has been on fundamental aspects of the ways in which domain walls arising at phase transitions evolve, interact with each other and interact with strain fields. It forms the basis for ongoing research focussed more specifically on "Materials for neuromorphic circuits", a Marie-Curie network funded by the EU. |
Sectors | Electronics |