Thermally Stimulated Luminescence Glow Peak Research Articles

Thermally stimulated luminescence of YBa 2Cu 3O 7 high-T c superconductors

Thermally stimulated luminescence (TSL) and x-ray luminescence of nominally undoped YBa 2Cu 3O 7 ceramics x-irradiated at low temperatures (20K) has been observed and reported for the first time. High purity YBa 2Cu 3O 7 exhibit two TSL glow-peaks, at 90 and 195K, with activation energies of 0.16 and 0.42 eV respectively. The TSL spectra contain a single emission band peaking at 3.65 eV. An additional, even more intense band, with a maximum at 2.8 eV is found in the low-temperature x-ray luminescence spectrum. The results are compared with existing data on the homologous GdBa 2Cu 3O 7 compound and a number of simple oxides. It is suggested that the defects involved in the x-ray-induced luminescence are intrinsic in nature, possibly related to oxygen vacancies.

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.

Glow-curve analysis of thermally stimulated luminescence in CaF2:Mn

Thermally stimulated luminescence (TSL) and emission spectra studies of CaF2:Mn have been conducted in the interval 80–300 K. X irradiation at 80 K and subsequent heating produces an intense TSL glow peak at 175 K with concomitant spectral emission consisting of a band whose maximum occurs at 495 nm with a full width at half-maximum of 0.290 eV. A detailed analysis of the 175-K TSL peak shows that the thermal process follows neither first- nor second-order kinetics but, in fact, obeys a 1.4-order kinetics expression. Pertinent parameters describing the glow peak are: frequency factor s=2.74×104 s−1, thermal activation energy E=0.234 eV, and heating rate β=0.079 K s−1. Previous work has shown that a TSL peak near 200 K, which produces 490-nm emission, is due to the de-excitation of substitutional Mn2+ ions. The glow peak was characterized by an activation energy of 0.5 eV with second-order kinetics. Although we agree with the physical model depicting TSL in CaF2:Mn, we believe that the process should be correctly described by 1.4-order kinetics.

Low-temperature thermally stimulated luminescence of high quality quartz

An investigation of the thermally stimulated luminescence (TSL) from quartz irradiated at 95 K has been made below room temperature. The synthetic quartz specimens were of very high quality with a Q of about 106. Such material contains few impurities and the TSL is weak. Nonetheless, it was determined that three regions of TSL glow peak interest exist. Region I (115–145 K) contains a single sharp peak having a maximum in its broad spectral emission at about 450 nm; Region II (145–185 K) is quite complex in structure, and is dependent upon defect content and sample treatment; Region III (185–270 K) can be eliminated by electrodiffusion (sweeping) techniques or by irradiation at temperatures above 250 K prior to the 95-K irradiation. Both Regions II and III show broadband spectral emission with maxima near 380 nm. The intensity of the TSL glow peak in Region III appears to correlate well with the presence of Al-Na+ and/or Al-Li+ centers as determined from other measurements, suggesting it may provide yet another method for quartz crystal quality evaluation.