Superconductivity induced by doping Ru in SrFe2−xRuxAs2

Abstract

Abstract:Using one-step solid state reaction method, we have successfully synthesized the superconductor SrFe 1-x Ru x As. X-ray diffraction indicates that the material has formed the ThCr 2 Si 2 -type structure with a space group I4/mmm. The systematic evolution of the lattice constants demonstrates that the Fe ions are successfully replaced by the Ru.By increasing the doping content of Ru, the spin-density-wave (SDW) transition in the parent compound is suppressed and superconductivity emerges. The maximum superconducting transition temperature is found at 13.5 K with the doping level of x = 0.7. The temperature dependence of DC magnetization confirms superconducting transitions at around 12 K. Our results indicate that similar to non-isoelectronic substitution, isoelectronic substitution contributes to changes in both the carrier concentration and internal pressure, and superconductivity could be induced by isoelectronic substitution.

Magnetic ordering and structural distortion in Ru-doped BaFe2As2single crystals studied by neutron and x-ray diffraction

“…Co, Ni, Rh). 32,33 Ru substitution on the Fe site in Ba(Fe 1−x Ru x ) 2 As 2 was recently reported to exhibit properties similar to the electron-doped BaFe 2 As 2 series but, again, at higher doping compositions. [34][35][36][37] The structural and AFM transition temperatures are suppressed with increasing x and superconductivity occurs at x ≈ 0.16.…”

Physical and magnetic properties ofBa(Fe1−xRux)2Thaler1, Ni2, Kracher3 et al. 2010Phys. Rev. B126261780View full textAdd to dashboardCite

“…However, recent polycrystalline studies in both the SrFe 2 As 2 [21,22] and BaFe 2 As 2 [7] systems show that Ru substitition on the Fe site suppresses the structural/magnetic phase transition and leads to superconductivity, indicating that this system may allow a direct comparison of nominally isovalent doping and electron doping TM substitution as well as pressure studies. Isovalent doping induced superconductivity, as pressure before it, indicates that whereas x and e are important parameters in parameterizing the phase transitions in these systems, changes in the unit cell parameter may be important as well.…”

Neutron diffraction study and anomalous negative thermal expansion in nonsuperconducting PrFe1−xRuxAsO

“…To better understand this, isoelectronic substitution on the Fe site has proved very instructive since unlike carrier doping it enables the study of materials without directly altering the Fermi level [19]. Moreover, isoelectronic doping with Ru can lead to superconductivity in certain Fe-oxypnictides, such as the 122 materials, BaFe 2−x Ru x As 2 [17] and SrFe 2−x Ru x As 2 [20]. In contrast, however, Ru/Fe substitution in 1111 materials has not been observed to lead to superconductivity even after the complete suppression of the structural and magnetic transitions: the studied systems include La(Fe,Ru)AsO [4], Pr(Fe,Ru)AsO [19], Sm(Fe,Ru)AsO and Gd(Fe,Ru)AsO [21].…”