As-75-NQR and Fe-57-NMR Studies on Heavily Overdoped LaFeAsO-based Superconductors

作者：Nitta Mariko^*; Mukuda Hidekazu; Yashima Mitsuharu; Kitaoka Yoshio; Shirage Parasharam M; Eisaki Hiroshi; Iyo Akira

来源：Journal of the Physical Society of Japan, 2012, 81: SB044.

• superconductivity
• iron-based oxypnictide
• LaFeAsO
• NQR

We report As-75-nuclear quadrupole resonance (NQR) and Fe-57-nuclear magnetic resonance (NMR) studies on heavily electron-doped LaFeAsO-based compounds with T-c = 5 and 8 K. The high quality of the samples was ensured by both narrow Fe-57-NMR and As-75-NQR spectra despite in the heavily overdoped state. Nuclear spin relaxation rate (1/T-1) measurements by As-75-NQR at zero field has revealed that a coherence peak just below T-c partially recovers in heavily electron-overdoped regimes where the nesting condition of hole and electron Fermi surfaces(FSs) becomes significantly worse. This result suggests that the interband scattering between the hole and electron FSs is suppressed by the heavily electron-overdoping because the hole FSs become smaller.

• 出版日期2012-12