75As-NMR studies on La FeAsO1-xFx (x=0.14) under a pressure of 3GPa

Abstract

75As-nuclear magnetic resonance (NMR) on an iron-based superconductor LaFeAsO1-xFx (x=0.14) was performed under a pressure of 3GPa. Enhancement of superconducting transition temperature Tc was confirmed from the relaxation rate 1/T1; Tc goes up to 40K by applying pressure up to 3GPa. 1/T1T, which is temperature independent just above Tc and gives a measure of the density of states (DOS) at the Fermi energy, enhances by applying pressure. These facts suggest that the increase of the DOS leads to the enhancement of Tc. On the other hand, anomalous behavior of 1/T1T observed at high temperatures is suppressed by applying pressure.

arXiv comment4pages, 5figures. Scheduled to appear in Journal of Phys. Soc. Jpn VoL.78 No.2 (2009)

References in corpus (13)

• Superconductivity at 38 K in the iron arsenide (Ba1-xKx)Fe2As2
• Unconventional sign-reversing superconductivity in LaFeAsO_(1-x)F_x
• Superconductivity at 43 K in Samarium-arsenide Oxides $SmFeAs{O}_{1-x}{F}_x$
• Unconventional pairing originating from disconnected Fermi surfaces in superconducting LaFeAsO${}_{1-x}$F${}_x$}
• LaFeAsO${}_{1-x}$F${}_x$: A low carrier density superconductor near itinerant magnetism
• Superconductivity in iron-based F-doped layered quaternary compound Nd[O1-xFx]FeAs
• Evolution from Itinerant Antiferromagnet to Unconventional Superconductor with Fluorine Doping in La(O_{1-x}F_{x})FeAs Revealed by ^{75}As and ^{139}La Nuclear Magnetic Resonance
• ${}^{75}$As NMR studies of superconducting LaO${}_{0.9}$F${}_{0.1}$FeAs
• Superconductivity under high pressure in LaFeAsO
• NMR relaxation rate in superconducting pnictides: extended $s_{\pm }$ scenario
• A possible ground state and its electronic structure of a mother material (LaOFeAs) of new superconductors
• 75As NQR/NMR Studies on Oxygen-deficient Iron-based Oxypnictide Superconductors LaFeAsO_{1-y} (y=0,0.25,0.4) and NdFeAsO_{0.6}
• A Generic Two-band Model for Unconventional Superconductivity and Spin-Density-Wave Order in Electron and Hole Doped Iron-Based Superconductors

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• Microwave response of superconducting pnictides: extended $s_{\pm }$ scenario
• Superconductivity under pressure in $R$FeAsO${}_{1-\mathrm{x}}$F${}_{\mathrm{x}}$ ($R$=La, Ce$-$Sm) by dc magnetization measurements
• Experimental evidence of $T_c$ enhancement without the influence of spin fluctuations: NMR study on LaFeAsO_{1-x}H_x under a pressure of 3.0 GPa
• Spatial competition of the ground states in 1111 iron pnictides
• Interplay between Fe 3d and Ce 4f magnetism and Kondo interaction in CeFeAs_{1-x}P_{x}O probed by ^{75}As and ^{31}P NMR
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