Magnetic ordering and structural distortion in Ru-doped BaFe 2 As 2 single crystals studied by neutron and x-ray diffraction

compounds (0≤x ≤0.246). Neutron and x-ray diffraction measurements demonstratethat, unlike for the electron-doped compounds, the structural and magnetic transitions remain coincident in tem-perature. Both the magnetic and structural transitions are gradually suppressed with increased Ru concentrationand coexist with superconductivity. For samples that are superconducting, we find strong competition betweensuperconductivity, the antiferromagnetic ordering, and the structural distortion.