Superconductivity in Pt Doped BaFe2As2

作者：Guo Yanfeng^*; Wang Xia; Li Jun; Zhang Shoubao; Yamaura Kazunari; Takayama Muromachi Eiji

来源：Journal of the Physical Society of Japan, 2012, 81(6): 064704.

DOI：10.1143/JPSJ.81.064704

• superconductivity
• BaFe2As2
• impurity effects
• high pressure synthesis
• antiferromagnetic metals

A high-pressure method was used to systematically dope an antiferromagnetically metallic compound, BaFe2As2, with Pt, and the doped compounds were studied using X-ray diffraction, energy dispersive X-ray spectroscopy, and by measuring the electrical resistivity, magnetic susceptibility, and specific heat. This method significantly increased the Pt doping level for BaFe2As2, resulting in a revision of the phase diagram proposed for BaFe2-xPtxAs2. The Pt doped system showed a dome-like superconductivity region in the thermal phase diagram (0.02 %26lt; x %26lt; 0.20) with an optimal T-c of 24.2K (x = 0.08), instead of the unusually wide superconductivity region found in early studies. Further doping beyond the optimal Pt concentration led to T-c continuously decreasing toward zero. The common superconducting feature of the 3d and 4d doped systems, BaFe2-xMxAs2 (M = Co, Ni, Rh, or Pd), was confirmed for the 5d doped system, BaFe2-xPtxAs2, which suggested that the electron-phonon coupling was insignificant at the superconducting state.

• 出版日期2012-6