Three-dimensional imaging of oxygen dopant distribution in Sr$_2$CuO$_{3+δ}$ by electron ptychography
arXiv:2608.20199
Hongbin Yang, Jinkwon Kim, Desheng Ma, Dasol Yoon, Darrell G. Schlom, David A. Muller
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Electron ptychography maps extra oxygen atoms sitting between Cu–O chains in a cuprate film—and finds they cluster where the crystal is stretched.
Read free explainer →Oxygen dopants play a critical role in tuning the properties of cuprate superconductors, yet it is challenging to visualize them at the atomic scale. Here, we use multislice electron ptychography to directly image oxygen dopants in a Sr2CuO3+delta film. We observe oxygen dopants at interstitial sites between the Cu-O chains, with a strong preference for clustering in tensile-strained regions, which are often associated with dislocations and interfacial steps. These findings indicate that the oxygen dopant distribution in cuprates is not random but rather sensitive to strain field, suggesting strain as a doping tuning parameter.