Superconductivity in the hypervalent compound Ba2Bi(Sb1-xBix)2 with a square-honeycomb lattice

Year: 2014 DOI: 10.7566/JPSJ.83.073705

Extra Information

Takeshi Yajima, Fumitaka Takeiri, Yasumasa Nozaki, Zhi Li, Takami Tohyama, Mark A. Green, Yoji Kobayashi, Hiroshi Kageyama.   Journal of the Physical Society of Japan, 2014, 83, 073705.


We studied the structural and physical properties of the hypervalent system Ba2Bi(Sb1−xBix)2 (0 ≤ x ≤ 1) with an anisotropic “square–honeycomb” layer. We found that the orthorhombic Ba2BiSb2 (x = 0) shows a charge density wave (CDW) transition at approximately 230 K accompanied by a significant elongation of the b-axis, indicating the quasi-one-dimensional nature along the b-axis in its electronic state, as supported by first-principles calculations. This CDW transition is rapidly suppressed with increasing x, leading to the appearance of superconductivity for 0.375 ≤ x ≤ 1. The superconducting transition temperature Tc increases slightly with x and the maximum Tc was 4.4 K for Ba2Bi3 (x = 1).