Ferroelectric, Ferroelastic and Multiferroic Domain Walls: a New Horizon in Nanoscale Functional Materials
Lead Research Organisation:
University of Cambridge
Department Name: Earth Sciences
Abstract
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Organisations
Publications
Carpenter M
(2022)
Static and dynamic strain relaxation associated with the paraelectric-antiferroelectric phase transition in PbZrO3
in Journal of Alloys and Compounds
Carpenter M
(2021)
Strain relaxation dynamics of multiferroic orthorhombic manganites
in Journal of Physics: Condensed Matter
Casals B
(2020)
Avalanches from charged domain wall motion in BaTiO 3 during ferroelectric switching
in APL Materials
Casals B
(2019)
Electric-field-induced avalanches and glassiness of mobile ferroelastic twin domains in cryogenic SrTi O 3
in Physical Review Research
Casals B
(2021)
The duration-energy-size enigma for acoustic emission
in Scientific Reports
Casals B
(2021)
Energy exponents of avalanches and Hausdorff dimensions of collapse patterns.
in Physical review. E
Casals B
(2021)
Avalanche criticality during ferroelectric/ferroelastic switching.
in Nature communications
Chen Y
(2022)
Acoustic emission spectra and statistics of dislocation movements in Fe40Mn40Co10Cr10 high entropy alloys
in Journal of Applied Physics
Chen Y
(2019)
Acoustic Emission from Porous Collapse and Moving Dislocations in Granular Mg-Ho Alloys under Compression and Tension
in Scientific Reports
Chen Y
(2020)
Avalanches and mixing behavior of porous 316L stainless steel under tension
in Applied Physics Letters
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 |