Prof. Catherine Dubourdieu (HZB and FU Berlin) and colleagues from the CEMES-CNRS in Toulouse, the College of Picardie in Amiens, and the Jozef Stefan Institute in Ljubljana have printed a examine in Nature Communications that totally investigates a very fascinating class of nanoislands on silicon and explores their suitability for electrical manipulation.
Nanostructures with distinctive electromagnetic patterns have potential makes use of in nanoelectronics and future info applied sciences. Nevertheless, this can be very troublesome to handle these patterns. HZB researchers have now investigated a novel class of nanoislands on silicon with intriguing chiral, whirling polar patterns that may be stabilized and even reversibly altered by an exterior electrical discipline.
Ferroelectrics on the nanoscale show varied polar and infrequently swirling (chiral) electromagnetic patterns, which mirror intriguing physics and maintain promise for future nanoelectronics. Think about ultra-high-density information storage or extremely energy-efficient field-effect transistors. Nevertheless, the sturdiness of those topological textures and the way they may be manipulated and guided by an exterior electrical or optical enter have confirmed to be a supply of rivalry.
Nanoislands on Silicon
We’ve got produced BaTiO3 nanostructures that type tiny islands on a silicon substrate.
Catherine Dubourdieu, Professor, Helmholtz-Zentrum Berlin für Materialien und Energie
The nano-islands are trapezoidal, with dimensions of 30–60 nm (on prime), and have secure polarization domains.
By high-quality tuning step one of the silicon wafer passivation, we might induce the nucleation of those nanoislands.
Dong-Jik Kim, Scientist, Helmholtz-Zentrum Berlin
Area Patterns Studied by PFM
An electrical discipline can reversibly transition between these domains. Vertical and lateral piezoresponse drive microscopy was used to analyze the area patterns.
Each the PFM measurement information and the section discipline modelling point out a centred, downward convergent polarisation, which inserts completely effectively with the knowledge from scanning transmission electron microscopy (STEM).
Ibukun Olaniyan, Ph.D. Pupil, Helmholtz-Zentrum Berlin für Materialien und Energie
Reversible Switching
The scientists recognized a swirling element across the nanoisland axis that generates chirality.
“The feel resembles a swirling vortex of liquid flowing right into a narrowing funnel. The middle down-converging nanodomains could be reversibly switched to middle up-diverging nanodomains by an exterior electrical discipline,” defined Dubourdieu.
“On this work, we’ve got proven that chiral topological textures could be stabilized by shaping nanostructures in an acceptable means,” concluded Dubourdieu.
The flexibility to supply and electrically alter chiral, swirling, polar patterns in BaTiO3 nanostructures exhibits nice promise for future functions.
This analysis was partially funded by the ERC Superior Grant LUCIOLE (101098216).
Journal Reference:
Olaniyan, I., et al. (2024) Switchable topological polar states in epitaxial BaTiO3 nanoislands on silicon. Nature Communications. doi.org/10.1038/s41467-024-54285-z
