Superconductivity in PT doped BaFe2As2

Article abstract of DOI:10.1143/JPSJ.81.064704

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 BaFe_2-xM_xAs₂. The Pt doped system showed a dome-like superconductivity region in the thermal phase diagram (0:02< x< 0:20) with an optimal Tc 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 Tc continuously decreasing toward zero. The common superconducting feature of the 3d and 4d doped systems, BaFe_2-xM_xAs₂ (M = Co, Ni, Rh, or Pd), was confirmed for the 5d doped system, BaFe_2-xM _xAs₂, which suggested that the electron-phonon coupling was insignificant at the superconducting state.