title: Superconductivity and structural distortion in BaPt2As2.
abstract: We report the synthesis of BaPt2As2 single crystals and the discovery of superconductivity and a structural phase transition in this compound by measuring the electrical resistivity, magnetic susceptibility and specific heat as well as the x-ray diffraction at low temperatures. BaPt2As2 crystallizes in the CaBe2Ge2-type tetragonal structure (P4/nmm) at room temperature and undergoes a first-order structural transition at TS ≃ 275 K, which is likely to be associated with a charge-density-wave (CDW) instability. BCS-like superconductivity with two subsequent transitions Tc1 ≃ 1.67 K and Tc2 ≃ 1.33 K is observed. Our results demonstrate that BaPt2As2 may serve as a new system for studying the interplay of superconductivity and the CDW order.
authors.affiliation: Center for Correlated Matter and Department of Physics, Zhejiang University, Hangzhou 310027, People's Republic of China.
authors.forename: W B
authors.initials: WB
authors.lastname: Jiang
authors.forename: C Y
authors.initials: CY
authors.lastname: Guo
authors.forename: Z F
authors.initials: ZF
authors.lastname: Weng
authors.forename: Y F
authors.initials: YF
authors.lastname: Wang
authors.forename: Y H
authors.initials: YH
authors.lastname: Chen
authors.forename: Y
authors.initials: Y
authors.lastname: Chen
authors.forename: G M
authors.initials: GM
authors.lastname: Pang
authors.forename: T
authors.initials: T
authors.lastname: Shang
authors.forename: X
authors.initials: X
authors.lastname: Lu
authors.forename: H Q
authors.initials: HQ
authors.lastname: Yuan