2014/02/21 by Hidekazu Mukuda, H. Mukuda, F. Engetsu +10
Business, Management and Accounting · Chemistry · Materials Science · Physics and Astronomy · #Antiferromagnetism #Chemistry #Condensed matter physics #Corporate Taxation and Avoidance #Crystallography #Iron-based superconductors research #Lattice (music) #Materials science #Pairing #Physics #Spin (aerodynamics) #Superconductivity #Tetrahedron #Thermodynamics #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.89.064511
published as Phys. Rev. B 89, 064511, (2014) · 6 pages, 8 figures, Accepted for publication in Phys. Rev. B
arxiv created 2014/02/21 · openalex publication_date 2014/02/25 · arxiv updated 2014/03/06 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Systematic 31P-NMR studies on LaFe(As_1\ensuremath-xPx)(O_1\ensuremath-yFy) with y=0.05 and 0.1 have revealed that the antiferromagnetic spin fluctuations (AFMSFs) at low energies are markedly enhanced around x=0.6 and 0.4, respectively, and as a result, Tc exhibits respective peaks at 24 and 27 K against the P substitution for As. This result demonstrates that the AFMSFs are responsible for the increase in Tc for LaFe(As_1\ensuremath-xPx)(O_1\ensuremath-yFy) as a primary mediator of the Cooper pairing. From a systematic comparison of AFMSFs with a series of (La_1\ensuremath-zYz)FeAsO_\ensuremathδ compounds in which Tc reaches 50 K for z=0.95, we remark that a moderate development of AFMSFs causes Tc to increase up to 50 K under the condition that the local lattice parameters of the FeAs tetrahedron approach those of the regular tetrahedron. We propose that Tc of Fe-pnictides exceeding 50 K is maximized under an intimate collaboration of the AFMSFs and other factors originating from the optimization of the local structure.