Mixed barium‐lead borate glasses studied by optical and vibrational spectroscopy

Abstract

Glasses of the ternary lead-barium borate series (70−x) B 2 O 3 -30 BaO-xPbO with x = 0.05 to 30 mol% were studied for their optical properties by photoluminescence (PL) and UV-Vis absorption spectroscopy. Variations in the s-p transition of Pb 2+ were followed as variations of the lead content and varying optical basicities of the glass. The UV cutoff of the undoped glass sample is observed at about 340 nm and increasing PbO addition results in a red shift of the optical absorption edge to 480 nm for the glass with x = 30 mol%. In lead barium borate glasses, the emission intensity increases up to 4 mol% PbO before decreasing at higher PbO levels. Additionally, the series was studied regarding structural variations by Raman and infrared spectroscopy. The fraction of tetrahedrally coordinated [BO 4/2 ] − and of trigonal borate units with nonbridging oxygen atoms (metaborate and pyroborate) increases with PbO addition. The molar volume of the prepared glasses is found to increase with increasing lead content. The glass basicity, as determined from the composition, correlates well with the position of the lead excitation band. K E Y W O R D SBorate glass, Pb 2+ fluorescence, Raman spectroscopy, photoluminescence, s-p transition

Silver dissolution and precipitation in an Na2O–ZnO–B2O3 metallization paste glass

“…The broad band at 445 cm −1 reveals metaborate units 37,38 or "loose" [BØ 4 ] − tetrahedral. 37,39 Bands observed here at ∼540 cm −1 can be assigned to [BØ 4 ] − -groups 36,37,40 and will be shown to belong to pentaborate later. The bands at 640, 730 cm −1 (NZB) or 721 cm −1 (Ag5NZB), and 970 cm −1 can be attributed to metaborate units in rings or chains.…”

“…These can also explain the band at 540 cm −1 mentioned earlier. The band at 937 cm −1 indicates [BØ 4 ] − ‐groups that cannot be further specified 36,37,40 …”

“…The band at 937 cm −1 indicates [BØ 4 ] − -groups that cannot be further specified. 36,37,40 The broad band >1000 cm −1 is assigned to NBOs in a large borate network as described previously. 42,45 B-O − stretching vibrations in metaborate [BØ 2 O] − -triangles in chains and rings should contribute to the band at 1421 cm −1 .…”

Structural, spectroscopic, and radiation shielding properties of Pb2+‐doped borate and phosphate glasses

“…At compositions below the metaborate stoichiometry 1M 2 O–1B 2 O 3 , [BØ 4 ] − (Ø denotes bridging oxygen, bO) units typically participate in well‐defined borate arrangements or superstructural units 14 . The short and intermediate range structural changes in the modified borate network directly affects the physical and optical properties, such as hardness, glass transition temperature, and fluorescence lifetimes 10,15–18 . However, the final glass structure has been shown to depend not only on the amount, but also on the type of the added modifier 17,19–21 .…”

Optical band gap and luminescence study of yttrium doped neodymium lead borotellurite glass system

“…The combination of lead oxide and borotellurite glass tend to enhance the glass properties. Based on previous research done by Othman et al, (2019), when lead oxide is added into borate glass, the crystallization of the glass was proven to be prevented [4].…”