Crystal structure and phase transitions across the metal-superconductor boundary in theSmFeAsO1−xFx(0≤x≤0.20)family

2008/06/24 by Serena Margadonna, Yasuhiro Takabayashi, Martin T. McDonald +7 · 120 citations
Business, Management and Accounting · Chemistry · Materials Science · Physics and Astronomy · #Chemistry #Condensed matter physics #Corporate Taxation and Avoidance #Crystal structure #Crystallography #Electrical resistivity and conductivity #Iron-based superconductors research #Materials science #Orthorhombic crystal system #Phase (matter) #Phase boundary #Physics #Quantum mechanics #Superconductivity #Tetragonal crystal system #cond-mat.supr-con

paper · pdf · doi:10.1103/physrevb.79.014503

published in Physical Review B 79(1) (American Physical Society)

arxiv created 2008/06/24 · openalex publication_date 2009/01/06 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05

Abstract

The fluorine-doped rare-earth iron oxyarsenides REFeAsO_1\ensuremath-xF_x (RE=rare earth) have recently emerged as a new family of high-temperature superconductors with transition temperatures (T_c) as high as 55 K. Here we use high-resolution synchrotron x-ray diffraction to study the structural properties of SmFeAsO_1\ensuremath-xF_x (0\ensuremath≤x\ensuremath≤0.20) in which superconductivity emerges near x\ensuremath∼0.07 and T_c increases monotonically with doping up to x\ensuremath∼0.20. We find that orthorhombic symmetry survives through the metal-superconductor boundary well into the superconducting regime and the structural distortion is only suppressed at doping levels, x\ensuremath≥0.15, when the superconducting phase becomes metrically tetragonal. Remarkably this crystal symmetry crossover coincides with reported drastic anomalies in the resistivity and the Hall coefficient, and a switch of the pressure coefficient of T_c from positive to negative, thereby implying that the low-temperature structure plays a key role in defining the electronic properties of these superconductors.

Citations

• Iron-based layered compound LaFeAsO is an antiferromagnetic semimetal
• Even Parity, Orbital Singlet, and Spin Triplet Pairing for SuperconductingLaFeAsO1−xFx
• Proximity of antiferromagnetism and superconductivity inLaFeAsO1−xFx: Effective Hamiltonian fromab initiostudies
• Crystallographic phase transition and high-Tcsuperconductivity in LaFeAsO:F
• Theory of electron nematic order in LaFeAsO
• Competing orders and spin-density-wave instability in La(O 1−x F x )FeAs
• A BCS-like gap in the superconductor SmFeAsO0.85F0.15
• Intrinsic properties of stoichiometric LaFePO
• Superconductivity in the iron-based F-doped layered quaternary compound Nd[O 1 − x F x ]FeAs
• Origin of the 150-K Anomaly in LaFeAsO: Competing Antiferromagnetic Interactions, Frustration, and a Structural Phase Transition
• Doping evolution of antiferromagnetic order and structural distortion inLaFeAsO1−xFx

Cited by

• Electronic and magnetic phase diagram of superconductors, SmFeAsO1−xFx
• Exploration of new superconductors and functional materials, and fabrication of superconducting tapes and wires of iron pnictides
• Microstructural evolution throughout the structural transition in 1111 oxypnictides
• Heat capacity measurements on FeAs-based compounds: a thermodynamic probe of electronic and magnetic states
• Superconductivity at 56 K in samarium-doped SrFeAsF