Jiang W B, Guo C Y, Weng Z F, Wang Y F, Chen Y H, Chen Y, Pang G M, Shang T, Lu X, Yuan H Q
Center for Correlated Matter and Department of Physics, Zhejiang University, Hangzhou 310027, People's Republic of China.
J Phys Condens Matter. 2015 Jan 21;27(2):022202. doi: 10.1088/0953-8984/27/2/022202. Epub 2014 Dec 8.
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.
我们报告了BaPt2As2单晶的合成，并通过在低温下测量电阻率、磁化率、比热以及x射线衍射，发现了该化合物中的超导性和结构相变。BaPt2As2在室温下结晶为CaBe2Ge2型四方结构（P4/nmm），并在TS≃275K时发生一级结构相变，这可能与电荷密度波（CDW）不稳定性有关。观察到具有两个相继转变温度Tc1≃1.67K和Tc2≃1.33K的类BCS超导性。我们的结果表明，BaPt2As2可能是研究超导性与CDW序相互作用的新体系。
