Nanoscale stacking disorder and Jahn-Teller distortion in Brochantite, Cu4SO4(OH)6, revealed by 3D electron diffraction
Year: 2026
Type: preprint
Abstract: Characterization of functional materials often neglects explicit modeling of structural disorder because of its complexity and the limitations of conventional experimental methods. Yet disorder can strongly affect material properties, and understanding its role is essential for establishing reliable structure-property relationships. Here, we address the long-standing structural complexity of brochantite, one of the most common basic copper sulfates, using 3D electron diffraction (3D ED) complemented by laboratory and synchrotron single-crystal X-ray diffraction. Measurements on dozens of crystals reveal nanoscale disorder, a new orthorhombic polytype, and a broad range of stacking-fault probabilities. The results demonstrate pronounced structural heterogeneity in brochantite and allow us to examine how different sulfate environments and stacking configurations correlate with the magnitude and orientation of Jahn-Teller distortions. High-pressure measurements further show that these distortions respond to changes in layer geometry and compression. Additionally, single-crystal X-ray investigations show unusual twinning in brochantite, whereas 3D ED data collected for nanocrystals supply individual crystal structures that are averaged out in larger crystals.
Source: ChemRxiv
Language: English
Subfield: Structural Biology
Domain: Life Sciences
Open Access status: green
Awards: G325287323, G6085164419
OpenAlex ID: W7213931800