Polarity and anti-distortive polarons in WO3 through epitaxial shear strain.
Authors:
- Ewout van der VeerEVEwout van der Veer
- Martin F SarottMSMartin F Sarott
- Jack T EcksteinJEJack T Eckstein
- Stijn FeringaSFStijn Feringa
- Johanna van Gent GonzálezJGJohanna van Gent González
- Majid AhmadiMAMajid Ahmadi
- Horatio R J CoxHCHoratio R J Cox
- Ellen M KiensEKEllen M Kiens
- Gertjan KosterGKGertjan Koster
- Bart J KooiBKBart J Kooi
Open Access
- 13 July 2026
- journal article
- Published by Springer Nature in Nature Communications
Abstract
Bestowing complementary metal-oxide semiconductor-compatible binary oxides with additional functionalities is a powerful strategy toward the realization of oxide electronics. Ideal candidates are thin films which display a strong sensitivity to strain, chemical doping or nanoscale confinement. Among these, crystalline tungsten trioxide WO3 exhibits exceptional structural flexibility, enabling a wide range of functionalities. Here we reveal the emergence of a polar phase in epitaxial WO3 thin films. We accomplish this by imposing epitaxial shear strain, which stabilizes a low-symmetry triclinic structure that persists up to large film thicknesses and elevated temperatures. At the atomic scale, a change in the oxygen octahedral tilt pattern facilitates this symmetry lowering into a polar phase, which manifests as a periodic in-plane polarized stripe domain configuration with needle-like bifurcations at the microscale. The stripe domain walls further exhibit a strongly enhanced electrical conductivity in conjunction with a pronounced reduction of a distortive structural mode, providing experimental evidence for anti-distortive polaronic transport recently predicted in WO3.Keywords
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Funding Information
- Horizon 2020 Framework Programme (861153)
- Horizon 2020 Framework Programme (101203197)
- Horizon 2020 Framework Programme (101135946)