엑스선 흡수 분광법을 이용한 Sr2VO3FeAs 연구

Abstract

The new iron-based superconductor Sr2VO3FeAs and electron-doped compound Sr2VO3Mn0.25Fe0.75As and hole-doped compound Sr2VO3Co0.25Fe0.75As are studied by X-ray absorption spectroscopy. All three samples show Fe2+ state. The electronic structure of Fe ion is similar to the other iron-based superconductor and shows no change due to doping. The V+3 ion is dominant for all three materials but mixed valence of V is observed. Mn and Co in each doped samples show typical covalent bonding nature. The difference of spectra between scrapped surface and fractured surface gives the possibility of grainboundary impurities.