Quantify the stress dependence of the secondary diffraction component

Determine the quantitative dependence of the secondary crystalline diffraction component in sputtered niobium films on intrinsic film stress, including the stress dependence of its relative fraction.

Background

X-ray diffraction scans are better described by a two-peak model than by a single-peak model for the analyzed films, providing evidence for an additional crystalline component that may be related to omega-niobium. The fitted peak amplitudes could in principle estimate the relative scattering contributions of the two components.

The number of diffraction scans and the associated parameter uncertainties are insufficient to establish how the secondary component varies with stress. A larger diffraction dataset is needed to determine that relationship robustly.

References

Although the fitted amplitudes may be interpreted as estimates of the relative scattering contributions from the two diffraction components, the limited number of diffraction scans and parameter uncertainties preclude a robust determination of the stress dependence of the secondary component fraction. We therefore rely primarily on the XRD data as evidence for an additional diffraction component, while the quantitative dependence of the additional component on film stress remains a subject for future investigation with a larger diffraction dataset.

— Evidence for a low-gap component in compressively stressed niobium thin films  (2609.26714 - Paustian et al., 22 Sep 2026) in Appendix, Section X-ray diffraction (XRD)