<i>In Situ</i> Imaging of Ferroelastic Domain Dynamics in CsPbBr<sub>3</sub> Perovskite Nanowires by Nanofocused Scanning X-ray Diffraction
Lucas A. B. Marçal, Eitan Oksenberg, Dmitry Dzhigaev, Susanna Hammarberg, Amnon Rothman, Alexander Björling, Eva Unger, Anders Mikkelsen, Ernesto Joselevich, Jesper Wallentin
Abstract
. Scanning X-ray diffraction with a 60 nm beam was used to retrieve local structural properties for temperatures up to 140 °C. We observed a single Bragg peak at room temperature, but at 80 °C, four new Bragg peaks appeared, originating in different real-space domains. The domains were arranged in periodic stripes in the center and with a hatched pattern close to the edges. Reciprocal space mapping at 80 °C was used to quantify the local strain and lattice tilts, revealing the ferroelastic nature of the domains. The domains display a partial stability to further temperature changes. Our results show the dynamics of nanoscale ferroelastic domain formation within a single-crystal perovskite nanostructure, which is important both for the fundamental understanding of these materials and for the development of perovskite-based devices.