Resistivity anomalies and intrinsic spin-orbit coupling in superconducting thin film solid solutions of Nb$_{1-x}$U$_x$ for $0.15 < x < 0.40$

Syed Akbar Hussain; Katie Brewer; Livina Onuegbu; Lottie M. Harding; Sean Giblin; Ross S. Springell; Christopher Bell

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arXiv · 2601.13285

Resistivity anomalies and intrinsic spin-orbit coupling in superconducting thin film solid solutions of Nb$_{1-x}$U$_x$ for $0.15 < x < 0.40$

Syed Akbar Hussain·Katie Brewer·Livina Onuegbu·Lottie M. Harding·Sean Giblin·Ross S. Springell·Christopher Bell

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Abstract

Polycrystalline thin films of $\mathrm{Nb}_{1-x}\mathrm{U}_{x}$ solid solutions with $0.15\leq x \leq 0.40$ were prepared via d.c. magnetron sputtering at ambient conditions. X-ray characterisation of the samples revealed a systematic shift of the (110) Nb Bragg reflection with U concentration, consistent with substitutional replacement of the Nb by U. Superconductivity was observed in all samples below $2$ K. Analysis of the superconducting critical fields revealed a direct scaling of the spin-orbit scattering and transport scattering times, indicating Elliott-Yafet-type spin relaxation in the system. Magnetoresistivity measurements showed a feature in the range $4$ K $\leq T \leq30$ K suggesting a possible a complex interplay between electron-electron interaction and localisation physics.

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Syed Akbar Hussain, Katie Brewer, Livina Onuegbu, Lottie M. Harding, Sean Giblin, Ross S. Springell, Christopher Bell. 2026-01-19. Resistivity anomalies and intrinsic spin-orbit coupling in superconducting thin film solid solutions of Nb$_{1-x}$U$_x$ for $0.15 < x < 0.40$. https://arxiv.org/abs/2601.13285

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