Local Environment of Fluorine Atoms in Sr[sub 2]Ca[sub n][sub – 1]Cu[sub n]O[sub 2][sub n][sub + δ]F[sub 2 ± ][sub y] (n = 2, 3) High-Temperature Superconductors Grown under High Pressure

Abstract

The local environment of fluorine atoms in Sr2Can − 1CunO2n + δF2 ± y (n = 2, 3) high-temperature superconductors (Tc = 99 and 111 K) is studied using soft x-ray emission and absorption spectroscopy. The fluorine spectra of the samples studied are found to be similar to those of SrF2, which supports the conjecture that fluorine atoms substitute for apex oxygen atoms and form double SrF layers.