Nanoscale textured superconductivity in Ru-substituted BaFe2As2 : a   challenge to a universal phase diagram for the pnictides
  75As NMR experiments were performed in Ba(Fe1-xRux)2As2 for x=0 to 80%. Magnetic fractions and NMR lineshapes demonstrate that Ru substitution destroys the antiferromagnetic (AF) order inhomogeneously with a magnetic moment distributed from 0.9 to 0 uB. Superconductivity emerges at intermediate Ru doping and coexists with AF order only in the regions where moments are smaller than ~0.3uB, resulting in an original nanoscale texture. This situation contrasts with that of Co substitution, challenging the apparent universality of the phase diagram in Fe-based superconductors. 
Yannis Laplace, Julien Bobroff, Veronique Brouet, Gaston Collin,   Florence Rullier-Albenque, Dorothee Colson, Anne Forget
cond-mat.str-el cond-mat.supr-con