2008/06/30 by H. Luetkens, H. -H. Klauss, H.‐H. Klauß +22 · 7 citations
Business, Management and Accounting · Materials Science · Physics and Astronomy · #Antiferromagnetism #Condensed matter physics #Corporate Taxation and Avoidance #Cuprate #Iron-based superconductors research #Muon spin spectroscopy #Phase (matter) #Phase diagram #Phase transition #Physics #Quantum critical point #Quantum mechanics #Quantum phase transition #Rare-earth and actinide compounds #Superconductivity #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1038/nmat2397
published as Nature Materials Letter April 2008, published online 22 February 2008 · 25 pages, 7 figures
openalex publication_date 2009/02/22 · arxiv created 2009/03/17 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The competition of magnetic order and superconductivity is a key element in the physics of all unconventional superconductors, e.g. in high-transition-temperature cuprates 1, heavy fermions 2 and organic superconductors3. Here superconductivity is often found close to a quantum critical point where long-range antiferromagnetic order is gradually suppressed as a function of a control parameter, e.g. charge carrier doping or pressure. It is believed that dynamic spin fluctuations associated with this quantum critical behaviour are crucial for the mechanism of superconductivity. Recently high-temperature superconductivity has been discovered in iron-pnictides providing a new class of unconventional superconductors4,5,6. Similar to other unconventional superconductors the parent compounds of the pnictides exhibit a magnetic ground state7,8 and superconductivity is induced upon charge carrier doping. In this Letter the structural and electronic phase diagram is investigated by means of x-ray scattering, MuSR and Moessbauer spectroscopy on the series LaO1-xFxFeAs. We find a discontinuous first-order-like change of the Neel temperature, the superconducting transition temperature and of the respective order parameters. Our results strongly question the relevance of quantum critical behaviour in ironpnictides and prove a strong coupling of the structural orthorhombic distortion and the magnetic order both disappearing at the phase boundary to the superconducting state.