Large enhancement of $T_{c}$ (= 35 K) in a sample synthesized from a starting composition of LaFeAsO$_{1-y}$H$_{x}$

ORAL

Abstract

Large enhancement of superconducting transition temperature ($T_{c})$ has been found in a sample synthesized from a nominal composition of LaFeAsO$_{1-y}$H$_{x}$. A hydroxide powder of La(OH)$_{3}$ is mixed with starting materials and the sample is synthesized under high-pressure. The sample shows as high as $T_{c}$ of 35 K (susceptibility onset) and 38 K (resistivity onset), while the maximum $T_{c}$ of an oxygen-deficient LaFeAsO$_{1-y}$ is 28 K. A large contraction of lattice is observed in the hydroxide-added samples.

Authors

  • Kichi Miyazawa

    • National Institute of Advanced Industrial Science and Technology and Department of Applied Electronics, Tokyo University of Science
  • Sigeki Ishida

    • National Institute of Advanced Industrial Science and Technology and Department of Physics, University of Tokyo
  • Kunihiro Kihou

    • National Institute of Advanced Industrial Science and Technology
  • Parasharam M. Shirage

    • National Institute of Advanced Industrial Science and Technology
  • Hijiri Kito

    • National Institute of Advanced Industrial Science and Technology
  • Chul Ho Lee

    • National Institute of Advanced Industrial Science and Technology
  • Shinichi Uchida

    • Department of Physics, University of Tokyo
  • Hiroshi Eisaki

    • Institute of Advanced Industrial Science and Technology
    • National Institute of Advanced Industrial Science and Technology
  • Kazuyasu Tokiwa

    • Department of Applied Electronics, Tokyo University of Science
  • Akira Iyo

    • National Institute of Advanced Industrial Science and Technology and Department of Applied Electronics, Tokyo University of Science