تهیه و مطالعه شیشه های ﺳﺪﻳﻢ تترابورات دوپه شده با اکسید تربیوم

Terbium oxide doped tetraborate glasses were prepared from the reaction of Tb2O3 and Na2B4O7 .10 H2O on reagent grade. At first, the base borate glass of Na2B4O7 was prepared by melting dehydrated borax at 1000 ˚C for 30 min and then the obtained base glass was crushed and powdered. Appropriate amounts of Tb2O3 (5-20 mol %) and Na2B4O7 powdered glass were mixed and melted at 1200 ˚C for 15 min. By transferring the melt in a cold steel sample holder and pressing, the final glasses were obtained. To avoid self crushing of the obtained glass samples, they were annealed at 300˚C for 1h. The density of the samples, measured by using Archimedes΄s principle, showed that the doping of Tb2O3 in Na2B4O7 increases the density of the glass. The infrared spectra of the glasses in the range of 4000 - 400 cm-1 shows that the addition of Tb2O3 did not introduce any new absorption band in the infrared spectrum of pure sodium tetraborate glass. Comparing of the IR spectral features of the Tb+3 doped glasses with undoped glass show that the evolution of the IR spectral bands is related to the structural changes produced by varying of Tb+3. UV Spectroscopic study of such glasses shows that the addition of terbium oxide shifts the optical absorption edges towards lower energies. The fluorescence properties of (1-x) Na2B4O7 .xTb2O3 glass system were investigated by means of   the emission Spectroscopy with excitation by 377 nm light. The glass presented intense ~ 550 nm green luminescence.