TY - JOUR AU - Rodríguez, M. AU - Aguiar, I. AU - Fornaro, L. AU - Hernandes, A. C. PY - 2011/11/19 Y2 - 2024/03/29 TI - Influence of PbO molar fraction and Se doping on borate glasses JF - Scientia Plena JA - Sci. Plena VL - 4 IS - 1 SE - DO - UR - https://www.scientiaplena.org.br/sp/article/view/665 SP - AB - <div>Glasses of xPbO(1-x)B2O3 composition, with x = 0.2, 0.4, 0.5 and 0.6, and doped with&nbsp;</div><div>Se (0.01, 0.02, and 0.03 mol) were synthesized from H3BO3, PbO, Pb3O4 and Se&nbsp;</div><div>powders, homogenized and then fused at about 700 - 800 &ordm;C. The fused mixing was&nbsp;</div><div>annealed at temperatures lower than the glass transition one, about 400 &ordm;C and during 3&nbsp;</div><div>hours. Samples were then slowly cooled down to room temperature. PbO concentration&nbsp;</div><div>correlates with an increase on the color intensity of the samples. Final glasses were cut,&nbsp;</div><div>mechanical etched and then characterized by spectrometry in the 400 - 830 nm range&nbsp;</div><div>and by differential scanning calorimetry (DSC) and thermal gravimetry (TG). The&nbsp;</div><div>influence of PbO and Se concentrations on the spectra was confirmed studying the&nbsp;</div><div>correlation between molar fraction and intensity of the 435 nm and 610 nm peaks. TG&nbsp;</div><div>results indicate that, when heated up to 800 &ordm;C, samples with Se decompose. However,&nbsp;</div><div>sample color as far as increases for the 435 nm absorption peak, indicating the possible&nbsp;</div><div>incorporation of Se to the glass structure. DSC diagrams show a glass transition in the&nbsp;</div><div>443-436 &ordm;C temperature range. DSC also indicate the glasses have up to three crystalline&nbsp;</div><div>phases. Future work will confirm these phases and Se incorporation by X-ray&nbsp;</div><div>diffraction.</div> ER -