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arXiv · 2510.10264

Vortex matter and strong pinning in underdoped PrFeAs(O,F) with atomic-sized defects

Andrey V. Sadakov·Vladimir A. Vlasenko·A. Yu. Levakhova·I. V. Zhuvagin·E. M. Fomina·V. A. Prudkoglyad·A. Y. Tsvetkov·A. S. Usoltsev·N. D. Zhigadlo
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Abstract

We present a comprehensive investigation of the field-dependent critical current density and pinning force, combined with a detailed analysis of the nanostructural defect landscape in single crystal of underdoped PrFeAs(O,F) superconductor. Our study demonstrates that for both in-plane and out-of-plane magnetic field orientations critical current density exhibits a strong pinning regime in intermediate fields across the entire temperature range. The dominant contribution to pinning originates from oxygen-to-fluorine substitutional defects, oxygen vacancies, which all act as point defects via a quasiparticle mean free path fluctuation mechanism. Scanning transmission electron microscope studies did not reveal any volume or surface defect types within the lattice.

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Andrey V. Sadakov, Vladimir A. Vlasenko, A. Yu. Levakhova, I. V. Zhuvagin, E. M. Fomina, V. A. Prudkoglyad, A. Y. Tsvetkov, A. S. Usoltsev, N. D. Zhigadlo. 2025-10-11. Vortex matter and strong pinning in underdoped PrFeAs(O,F) with atomic-sized defects. https://doi.org/10.1103/d4t9-gk9z

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