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arXiv · 1311.1303

Superconductivity in Ca1-xLaxFeAs2: A Novel 112-Type Iron Pnictide with Arsenic Zigzag Bonds

Naoyuki Katayama·Kazutaka Kudo·Seiichiro Onari·Tasuku Mizukami·Kento Sugawara·Yuki Sugiyama·Yutaka Kitahama·Keita Iba·Kazunori Fujimura·Naoki Nishimoto·Minoru Nohara·Hiroshi Sawa
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Abstract

We report superconductivity in the novel 112-type iron-based compound Ca1-xLaxFeAs2. Single-crystal X-ray diffraction analysis revealed that the compound crystallizes in a monoclinic structure (space group P21), in which Fe2As2 layers alternate with Ca2As2 spacer layers such that monovalent arsenic forms zigzag chains. Superconductivity with a transition temperature (Tc) of 34 K was observed for the x = 0.1 sample, while the x = 0.21 sample exhibited trace superconductivity at 45 K. First-principles band calculations demonstrated the presence of almost cylindrical Fermi surfaces, favorable for the high Tc in La-doped CaFeAs2.

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Naoyuki Katayama, Kazutaka Kudo, Seiichiro Onari, Tasuku Mizukami, Kento Sugawara, Yuki Sugiyama, Yutaka Kitahama, Keita Iba, Kazunori Fujimura, Naoki Nishimoto, Minoru Nohara, Hiroshi Sawa. 2013-11-06. Superconductivity in Ca1-xLaxFeAs2: A Novel 112-Type Iron Pnictide with Arsenic Zigzag Bonds. https://doi.org/10.7566/jpsj.82.123702

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