Parallel suppression of superconductivity and Fe moment in the collapsed tetragonal phase of Ca0.67Sr0.33Fe2As2 under pressure

Abstract

Using non-resonant Fe K-beta x-ray emission spectroscopy, we reveal that Sr-doping of CaFe2As2 decouples the Fe moment from the volume collapse transition, yielding a collapsed-tetragonal, paramagnetic normal state out of which superconductivity develops. X-ray diffraction measurements implicate the c-axis lattice parameter as the controlling criterion for the Fe moment, promoting a generic description for the appearance of pressure-induced superconductivity in the alkaline-earth-based 122 ferropnictides (AFe2As2). The evolution of the superconducting critical temperature with pressure lends support to theories for superconductivity involving unconventional pairing mediated by magnetic fluctuations.

References in corpus (12)

• High-temperature superconductivity in iron-based materials
• Structural and magnetic phase diagram of CeFeAsO1-xFx and its relationship to high-temperature superconductivity
• Effect of Structural Parameters on Superconductivity in Fluorine-Free LnFeAsO1-y (Ln=La,Nd)
• Is LaO${}_{1-x}$F${}_x$FeAs an electron-phonon superconductor ?
• Pressure-induced volume-collapsed tetragonal phase of CaFe2As2 as seen via neutron scattering
• Magnetism in Fe-based superconductors
• The Unprecedented Giant Coupling of Fe-spin State and the As-As Hybridization in Iron-Pnictide
• The Absence of Superconductivity in Single Phase CaFe2As2 under Hydrostatic Pressure
• Lattice collapse and quenching of magnetism in CaFe2As2 under pressure: A single crystal neutron and x-ray diffraction investigation
• Electrical Resistivity and Specific Heat of EuFe2As2 Single Crystals: Magnetic homologue of SrFe2As2
• Superconducting and ferromagnetic phases induced by lattice distortions in SrFe2As2
• Spin-state transition in the Fe-pnictides

Cited by in corpus (4)

• Structural origin of the anomalous temperature dependence of the local magnetic moments in the CaFe${}_2$As${}_2$ family of materials
• The collapsed tetragonal phase as a strongly covalent and fully nonmagnetic state: persistent magnetism with interlayer As-As bond formation in Rh-doped Ca${}_{0.8}$Sr${}_{0.2}$Fe${}_2$As${}_2$
• Pressure-induced suppression of ferromagnetism in the itinerant ferromagnet LaCrSb${}_3$
• Influence of growth flux solvent on anneal-tuning of ground states in CaFe2As2