Comparison of the Superconducting Properties of Potassium Iron Selenides with Isovalent Substitution
Year: 2025
Type: article
Abstract: Using incoherent multiple Andreev reflection effect spectroscopy, we have studied the properties of the superconducting phase of (K,Na) x Fe2–y Se2 and K z Fe2 – y (Se,S)2 iron selenides with critical temperatures $${{T}_{c}} \approx 27{-} 31$$ K. In both compositions, we directly show a presence of a single superconducting order parameter, and directly determine its magnitude and temperature dependence. The obtained characteristic ratio $$2\Delta (0){\text{/}}{{k}_{B}}{{T}_{c}} \approx 4.1{-} 4.6$$ results from a strong coupling in the electron bands. The similarity between the superconducting gap structure and the observed $$\Delta (0)$$ scaling with critical temperature points to a uniform Cooper pairing mechanism in (K,Na) x Fe2–y Se2 and K z Fe2–y (Se,S)2 iron selenides.
Authors: T. E. Kuzmicheva, S. A. Kuzmichev, A. D. Ilina, I. A. Nikitchenkov, Ye. O. Rakhmanov, A. I. Shilov, I. V. Morozov
Language: English
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
OpenAlex ID: W4409445441