Upper critical field and critical current density of Zn and Mn substituted FeSe 0.4 Te 0.6 single crystals

作者：Ke Shi, Minjie Zhang, Yongqi Han, Yu Zhao, Ze Wang, Langsheng Ling, Wei Tong, Chuanying Xi, Li Pi, Shunli Ni, Menghu Zhou, Zhaosheng Wang · 发表于：Superconductor Science and Technology · 年份：2025 · DOI：10.1088/1361-6668/add427 · 被引用次数：2 · 研究领域：Iron-based superconductors research、Chalcogenide Semiconductor Thin Films、Rare-earth and actinide compounds

Abstract By electrical transport and magnetization measurements under magnetic fields up to 42 T and 35 T respectively, the μ 0 H c 2 − T phase diagrams and the critical current density J c were determined for Fe 0.99 Zn 0.01 Se 0.4 Te 0.6 and Fe 0.99 Mn 0.01 Se 0.4 Te 0.6 single crystals. Fitting with the Werthamer–Helfand–Hohenberg model yields zero-temperature critical fields of H c 2 a b = 46.6 T and H c 2 c = 46.7 T for Fe 0.99 Zn 0.01 Se 0.4 Te 0.6 , along with H c 2 a b = 48.8 T and H c 2 c = 48.3 T for Fe 0.99 Mn 0.01 Se 0.4 Te 0.6 —all exceeding the BCS weak-coupling Pauli limit ( ≈ 26 T ). The H c 2 anisotropy approaches 1 as temperature decreases to 0 K for both samples. The critical current density J c reaches 4.3 × 10 5 A cm − 2 for Zn-substituted and <jats:inl