Interfaces without defects
Previously, such superstructures were produced from periodically arranged layers of different materials. However, the interfaces between different materials are often not perfectly defined, and defects occur that massively reduce the propagation of phonons and thus the thermal conductivity.
In their recent investigations, the researchers proved that such interference effects do not occur if the material of the layers is identical but the arrangement of the atoms differs. And although the layers consist of the same material, the phononic properties only change through the rotation of the layers against each other. Until now it was not clear whether these novel systems behave like conventional superlattices.
The study is a collaboration between the Department of Physics at the University of Basel, the Swiss Nanoscience Institute (SNI), the Eindhoven University of Technology, the Autonomous University of Barcelona and the Institut de Ciència de Materials de Barcelona.
Marta De Luca, Claudia Fasolato, Marcel A. Verheijen, Yizhen Ren, Milo Y. Swinkels, Sebastian Kölling, Erik, P. A. M. Bakkers, Riccardo Rurali, Xavier Cartoixà, Ilaria Zardo
Phonon Engineering in Twinning Superlattice Nanowires
Nano Letters (2019), doi: 10.1021/acs.nanolett.9b01775
Prof. Dr. Ilaria Zardo, Departement Physik, Universität Basel, Tel. +41 61 207 37 34, E-Mail: firstname.lastname@example.org