Chiral lone-pair helices with handedness coupling to electric-strain fields
Fuente:
arXiv
Guardado en:
| Autores principales: | , , , , , , , |
|---|---|
| Formato: | Preprint |
| Publicado: |
2025
|
| Materias: | |
| Acceso en línea: | |
| Etiquetas: |
Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
|
| _version_ | 1866916859000913920 |
|---|---|
| author | Zeiger, C. R. Dragland, R. S. Sjökvist, R. Beanland, R. Meier, D. Grande, T. Senn, M. S. Grendal, O. G. |
| author_facet | Zeiger, C. R. Dragland, R. S. Sjökvist, R. Beanland, R. Meier, D. Grande, T. Senn, M. S. Grendal, O. G. |
| contents | Ferrochiral materials with an achiral-to-chiral phase transition and switchable chirality have unique application opportunities, enabling control of the angular momentum of circularly polarized lattice vibrations (chiral phonons) and chirality-related electronic phenomena. Materials that fall into this class are, however, extremely rare, and often accompanied by other types of ferroic order that interfere with the ferrochiral responses. In this work, we demonstrate ferrochirality in two tetragonal tungsten bronzes, K4Bi2Nb10O30 and Rb4Bi2Nb10O30. Using high-resolution X-ray powder diffraction combined with transmission electron microscopy, we solve the incommensurately modulated and chiral structures. Temperature dependent X-ray powder diffraction reveals that both materials undergo an achiral-to-chiral phase transition from P4/mbm to P4212(00γ)q00. The chirality originates from a cooperative helical displacement of Bi3+ atoms perpendicular to the c direction and represents the primary order parameter. As a secondary effect of the ferrochiral order, a spatially varying piezoelectric response is observed, consistent with the polycrystalline nature of the investigated materials. Through invariant analysis, an external electric-strain-field coupling with the piezoelectricity is proposed as a conjugate field for switching chirality, establishing tetragonal tungsten bronzes as a versatile playground for the emergent field of ferrochirality. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2507_17473 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Chiral lone-pair helices with handedness coupling to electric-strain fields Zeiger, C. R. Dragland, R. S. Sjökvist, R. Beanland, R. Meier, D. Grande, T. Senn, M. S. Grendal, O. G. Materials Science Ferrochiral materials with an achiral-to-chiral phase transition and switchable chirality have unique application opportunities, enabling control of the angular momentum of circularly polarized lattice vibrations (chiral phonons) and chirality-related electronic phenomena. Materials that fall into this class are, however, extremely rare, and often accompanied by other types of ferroic order that interfere with the ferrochiral responses. In this work, we demonstrate ferrochirality in two tetragonal tungsten bronzes, K4Bi2Nb10O30 and Rb4Bi2Nb10O30. Using high-resolution X-ray powder diffraction combined with transmission electron microscopy, we solve the incommensurately modulated and chiral structures. Temperature dependent X-ray powder diffraction reveals that both materials undergo an achiral-to-chiral phase transition from P4/mbm to P4212(00γ)q00. The chirality originates from a cooperative helical displacement of Bi3+ atoms perpendicular to the c direction and represents the primary order parameter. As a secondary effect of the ferrochiral order, a spatially varying piezoelectric response is observed, consistent with the polycrystalline nature of the investigated materials. Through invariant analysis, an external electric-strain-field coupling with the piezoelectricity is proposed as a conjugate field for switching chirality, establishing tetragonal tungsten bronzes as a versatile playground for the emergent field of ferrochirality. |
| title | Chiral lone-pair helices with handedness coupling to electric-strain fields |
| topic | Materials Science |
| url | https://arxiv.org/abs/2507.17473 |