Yan Chen, Dillon D. Fong, F. William Herbert, Julien Rault, Jean-Pascal Rueff, Nikolai Tsvetkov, and Bilge Yildiz,* Modified Oxygen Defect Chemistry at Transition Metal Oxide Hetero-structures Probed by Hard X-Ray Photoelectron Spectroscopy and X-ray Diffraction，Chemistry of Materials (2018) DOI: 10.1021/acs.chemmater.8b00808