Luminescence in thermally annealed and electron irradiated Bi_2Sr_2CaCu_2O_x ceramics

Abstract

The effect of vacuum thermal annealing and electron irradiation on the luminescence of Bi_2Sr_2CaCu-2O_x ceramics has been investigated by cathodoluminescence (CL) in the scanning electron microscope (SEM), time-resolved photoluminescence (PL), and micro-Raman spectroscopy. It is found that a luminescence band centered at 2.4 eV (520 nm) is enhanced after either thermal annealing or electron irradiation treatments. The experimental results suggest that the appearance of this band is related to changes of the oxygen content induced by the treatments undergone by the sample. The effect appears to be stronger in electron irradiated samples, for which the structural changes were revealed to be more severe by micro-Raman spectroscopy.