Researchers affiliated with institutions in India and the United States examined how oxygen vacancies in NdBaCo₂O₅₊δ cobaltate relate to electrical transport. In an October 9 arXiv preprint, the team analyzed an oxygen-deficient double perovskite with nominal δ≈0.65 using X-ray absorption near-edge structure (XANES), alongside multiple-scattering and density-functional-theory calculations. The paper has not undergone peer review.

Spectral features at the Co K, Ba LIII and Nd LIII edges suggested the studied sample may be closer to δ≈0.75. The cobalt-edge analysis was interpreted as indicating oxygen vacancies at basal sites as well as apical sites; the authors linked this distribution to the observed magnetic inhomogeneity and variable-range hopping transport. Oxygen-ion mobility and faster sensors are discussed as possible directions, but the study does not build or test a sensor. The first page lists author affiliations at IIT Mandi in India and Brookhaven National Laboratory in New York.