Electronic Localization Due to Fluorine in YBa2Cu3OxFy Superconducting Materials

摘要

High-Tc superconducting materials, YBa2Cu3OxFy with x÷6.89 and 0.25÷y÷0.35, were prepared and Studied by X-ray diffraction, magnetic susceptibility and resistivity measurement. Under given conditions, reproducible resistivities were obtained, which increased with increase in the amount of fluorine. The introduced fluorine atoms were found to be localized in pyramidal Cu-O units rather than in Cu-O chains. It is suggested that the localized fluorine atom increases the electronic lolcalization of the superconducting electrons.