Oxidation effect on the stability of α-Tantalum/Al₂O₃ heterostructures

In this research, we present computational results on the influence of oxidation on the α-Ta/Al₂O₃-based superconducting resonators. Using density functional theory calculations, the interactions at the interface between Ta and the Al₂O₃ nanoparticle substrate are analyzed, identifying the preferential epitaxial growth directions of Ta on Al₂O₃. Additionally, we explore the oxidation process at the interface, where we found a TaO layer formation at the interface of the heterojunctions. Substrate oxygen atoms are located at the first interface layers and do not diffuse into the α-Ta film. Our results highlight Al₂O₃ as a promising substrate for fabricating high-performance superconducting resonators.

Acknowledgments

We thank NSF- ExpandQISE: award number 2328747, and the DGAPA-UNAM project IG101124 for the partial financial support.

Calculations were performed in the DGCTIC-UNAM Supercomputing Center, Project LANCAD-UNAM-DGTIC-368.