We have recently reported two superconductors with the d1 square lattice, BaTi2Sb2O (Tc = 1:2 K) and BaTi 2Bi2O (Tc = 4:6 K). In order to find a clue behind the superconductivity of these materials, we synthesized isovalent solid solutions of BaTi2(As1-xSbx)2O and BaTi 2(Sb1-yBiy)2O. Despite Vegard's law behavior in cell constants, a two-dome structure in Tc was observed with two distinct superconducting phases ("0:9 ≤ x; y ≤ 0:3" and "0:6 ≤ y ≤ 1") separated by a metallic phase. This result implies a multiband nature at the Fermi surface in BaTi2Pn 2O. © 2013 The Physical Society of Japan.
ASJC Scopus subject areas
- Physics and Astronomy(all)