Synthesis of large FeSe superconductor crystals via ion release/introduction and property characterization

Yuan Dongna¹, Huang Yulong¹, Ni Shunli¹, Zhou Huaxue¹, Mao Yiyuan¹, Hu Wei¹, Yuan Jie¹, Jin Kui¹, Zhang Guangming³, Dong Xiaoli^{1, 2, †,}, Zhou Fang^{1, 2, ‡,}

The in-plane electrical resistance R_ab(T) near the superconducting transition under the magnetic fields up to 9 T. In the inset, the hollow symbols are the upper critical fields H_c2(T) from the 10%, 50%, and 90% resistance drops; the solid lines correspond to the H_c2(T) fitted by the two-band model, yielding the zero-temperature H_c2(T = 0) of 13.2 T, 14.9 T, and 16.7 T, respectively.