title: Emergence of superconductivity at 45 K by lanthanum and phosphorus co-doping of CaFe₂As₂.
abstract: Co-doping of lanthanum and phosphorus in CaFe₂As₂ induces superconductivity at 45 K. This superconducting transition temperature is higher than the 38 K transition in Ba₁-xKxFe₂As₂, which is the maximum found thus far among the 122 phases. Superconductivity with a substantial shielding volume fraction was observed at 0.12 ≤ x ≤ 0.18 and y = 0.06 in Ca₁-xLaxFe₂(As₁-yPy)₂. The superconducting phase of the present system seems to be not adjacent to an antiferromagnetic phase.
authors.affiliation: Department of Physics, Okayama University, Okayama 700-8530, Japan. kudo@science.okayama-u.ac.jp
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Kudo
authors.forename: Keita
authors.initials: K
authors.lastname: Iba
authors.forename: Masaya
authors.initials: M
authors.lastname: Takasuga
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kitahama
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Matsumura
authors.forename: Masataka
authors.initials: M
authors.lastname: Danura
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Nogami
authors.forename: Minoru
authors.initials: M
authors.lastname: Nohara