Hydrogen response to high‐density dislocations in bulk perovskite oxide SrTiO₃

Hydrogen plays an increasingly important role in green energy technologies. For instance, proton-conducting oxides with high performance for fuel cell components or electrolyzers need to be developed. However, this requires a fundamental understanding of hydrogen-defects interactions. Although point defects and grain boundaries in oxides have been extensively studied, the role of dislocations as line defects remains less understood, primarily due to the challenge for effective dislocation engineering in brittle oxides. In this work, we demonstrate the impact of dislocations in bulk single-crystal perovskite oxide SrTiO3 on hydrogen uptake and diffusion using deuterium as tracer. Dislocations with a high density up to ∼1014/m2 were mechanically introduced at room temperature. Exposing this dislocation-rich region and the reference regions (with a dislocation density of ∼1010/m2) to deuterium at 400°C for 1 h, followed by secondary ion mass spectrometry measurements, we observed a ∼100 times increase in deuterium incorporation in the dislocation-rich region. The result suggests that dislocations in oxides can act as an effective reservoir for deuterium. ... mehrThis proof-of-concept brings new insights into the emerging hydrogen-dislocation interactions in functional oxides.