Thermally stimulated luminescence from rare-earth-doped barium copper oxides

We report the first thermally stimulated luminescence (TSL) and emission-spectra measurements of x-ray-induced defects in ${\mathrm{Ho}}_{1.5}{\mathrm{Ba}}_{1.5}{\mathrm{Cu}}_2{\mathrm{O}}_x$ and $\mathrm{Gd}{\mathrm{Ba}}_2{\mathrm{Cu}}_3{\mathrm{O}}_x$ in the temperature interval 80-300 K. The Gd-doped oxide exhibits a single TSL glow peak at 195 K with concomitant single-band emission with maximum at 500 nm. Two TSL glow peaks (160 and 172 K) are observed in ${\mathrm{Ho}}_{1.5}{\mathrm{Ba}}_{1.5}{\mathrm{Cu}}_2{\mathrm{O}}_x$, whose spectral emission is characterized by complex, temperature-dependent maxima at 450 and 660 nm. Possible defect mechanisms are discussed.