Paper on NdTiO3-SrTiO3 Interfaces Published in Physical Review Letters

A collaborative paper led by Bharat Jalan’s group at the University of Minnesota and our group at Pacific Northwest National Lab
exploring the effects of different defects at the interface between SrTiO3 (STO) and NdTiO3 (NTO) on the electronic behavior of the two-dimensional electron gas in this system has been published in Physical Review Letters! We find that the electronic behavior is highly dependent on both Nd:Ti stoichiometry and on the level of oxidation in the NTO layer. Somewhat surprisingly, our x-ray photoelectron spectroscopy measurements and density functional theory analysis indicate that oxygen interstitials may diffuse from the surface into the bulk of the NTO film, changing the Ti formal valence from 3+ to 4+. This has drastic effects on the electronic behavior of the conducting interface between STO and NTO, which will help us understand how to better engineer these materials going forward.