The F-doped LaFeAsO-a recently discovered superconductor with the high Tc of 26 K-has been studied using the resistivity (ρ), magnetic-susceptibility (χ), and heat-capacity (Cp) measurements in the F doping range 0≤x≤0.14 (LaFeAsO1-x Fx). In the low-temperature region, a T3 lnT term in Cp and a T2 term in χ -which are derived from the spin fluctuation-are observed. The nearly ferromagnetic nature evidenced by a large Wilson ratio (6.5 for x=0 and 11.2 for x=0.025) suggests that the superconductivity in the LaFeAsO system is mediated by ferromagnetic spin fluctuation.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2008 Jul 29|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics