Iron arsenides with three-dimensional FeAs layer networks: Ca_n(n+1)/2(Fe_1-xPt_x)_(2+3n)Pt_n(n-1)/2As_(n+1)(n+2)/2 (n = 2, 3).

ABSTRACT: We report the comprehensive studies between synchrotron X-ray diffraction, electrical resistivity and magnetic susceptibility experiments for the iron arsenides Ca_n(n+1)/2(Fe_1-xPt_x)_(2+3n)Pt_n(n-1)/2As_(n+1)(n+2)/2 for n = 2 and 3. Both structures crystallize in the monoclinic space group P2₁/m (#11) with three-dimensional FeAs structures. The horizontal FeAs layers are bridged by inclined FeAs planes through edge-sharing FeAs5 square pyramids, resulting in triangular tunneling structures rather than the simple layered structures found in conventional iron arsenides. n = 3 system shows a sign of superconductivity with a small volume fraction. Our first-principles calculations of these systems clearly indicate that the Fermi surfaces originate from strong Fe-3d characters and the three-dimensional nature of the electric structures for both systems, thus offering the playgrounds to study the effects of dimensionality on high T_c superconductivity.

SUBMITTER: Katayama N 

PROVIDER: S-EPMC5171830 | biostudies-literature | 2016 Dec

REPOSITORIES: biostudies-literature