Niobium hydride formation in superconducting qubit thin films
Year: 2025
Type: article
Abstract: The formation of nonsuperconducting hydrides in 160–170-nm-thick films of niobium is examined. We identify six elastically distinct orientation relationships ɛ − Nb 4 H 3 takes within the matrix, solid-solution α − NbH x phase. We employ a phase field model to assess the impact of elastic energy induced by the strain of phase transformation on the morphology and transformation dynamics of ɛ precipitates within a thin film. We consider the dimensions of the thin film, crystallographic growth direction, and diffusion rates to predict the timescale of hydride evolution. Leveraging the finite element method, we predict two-dimensional and three-dimensional equilibrium shapes of ɛ -hydrides within a bulk sample and in a thin film that has a traction-free surface. Our results suggest that niobium hydrides migrate to the free surface of the film. Precipitates which reach the free surface coarsen, while precipitates within the film dissolve. Precipitates in both two dimensions and three dimensions experience a repulsive interaction force at the free surface, that is attractive in the bulk, shown in experiment and theory of previous studies.
Source: Physical Review Materials
DOI: 10.1103/v27k-y5fb
Authors: Tyler J. Leibengood, Pierre-Clément A. Simon, P. Graham Pritchard, James M. Rondinelli, Peter W. Voorhees
Institutions: Northwestern University, Idaho National Laboratory
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Awards: G2812568293, G42916606, G4483802702
OpenAlex ID: W4411204815