论文标题
新型薰衣草相BAIR2的高压合成和超导性
High-pressure synthesis and superconductivity of the novel Laves phase BaIr2
论文作者
论文摘要
包括IR和PT的5D过渡金属的超导体已被广泛探索，因为它们具有由强旋转轨道相互作用（SOI）引起的独特超导性的潜力。我们成功合成了BAIR2，这是MGCU2型AM2中的最后一个laves阶段（a = ca，sr，ba; m = rh，pd，ir，pt）。 BAIR2通过BA和IR粉末之间的固态反应在3.3 GPA的压力下以925 C结晶；发现它具有最长的A晶格常数为8.038（1）A中的AM2中。 BAIR2在2.7 K. Bair2的过渡温度（TC）下表现出散装超导性。电子 - 音波耦合常数和归一化的比热跳跃分别测量为0.63和1.2，表明BAIR2是弱耦合超导体。 BAIR2的电子结构计算表明，IR-5D状态在费米能量（EF）处主要占主导地位，而在EF处的状态密度受到SOI的强烈影响，例如CAIR2和SRIR2。
Superconductors comprising 5d transition metals of Ir and Pt have been widely explored because they have the potential of unique superconductivity caused by the strong spin-orbit interaction (SOI). We successfully synthesized BaIr2, the last Laves phase remaining unsynthesized in the MgCu2-type AM2 (A = Ca, Sr, Ba; M = Rh, Pd, Ir, Pt). BaIr2 was crystallized at 925 C under a pressure of 3.3 GPa via a solid-state reaction between Ba and Ir powders; it was found to have the longest a-lattice constant of 8.038(1) A among AM2. BaIr2 exhibited bulk superconductivity at a transition temperature (Tc) of 2.7 K. BaIr2 was found to have a type-II superconductor with an upper critical field of 67.7 kOe, which was above the Pauli paramagnetic limit (50 kOe). The electron-phonon coupling constant and normalized specific heat jump were measured to be 0.63 and 1.2, respectively, indicating that BaIr2 is a weak-coupling superconductor. The electronic-structure calculations for BaIr2 revealed that the Ir-5d states are dominant at the Fermi energy (EF) and the density of states at the EF is strongly affected by SOI as in the case of CaIr2 and SrIr2.
