Superconducting Transition Temperatures of up to 47K from Simultaneous Rare-Earth Element and Antimony Doping of 112-Type CaFeAs2

作者：Kudo Kazutaka^*; Kitahama Yutaka; Fujimura Kazunori; Mizukami Tasuku; Ota Hiromi; Nohara Minoru

来源：Journal of the Physical Society of Japan, 2014, 83(9): 093705.

DOI：10.7566/JPSJ.83.093705

The effects of simultaneous Sb doping on the superconductivity of 112-type Ca1-xRExFeAs2 (RE = La, Ce, Pr, and Nd) were studied through measurements of the magnetization and electrical resistivity. In Sb-free materials, the superconducting transition temperature T-c of the La-doped sample was 35 K, while those of the Pr- and Nd-doped samples were similar to 10 K; no superconductivity was observed in the Ce-doped sample. Sb doping increased the T-c of all RE-doped samples: T-c increased to 47, 43, 43, and 43K for RE = La, Ce, Pr, and Nd, respectively. We also found that the enhanced superconductivity results from the increase in the lattice parameter b, which increases the As-Fe-As bond angle to be closer to the ideal tetrahedron value. These observations provide insight for further increasing the T-c of the 112 phase.

• 出版日期2014-9