Colorless SnO- and Sb₂O₃-containing borate and borosilicate glasses with small photoelastic and high refractive properties

Abstract

We examined the relationship between optical properties and structures of 5s2-type cations such as Sn2+- and Sb3+-containing borate and borosilicate glass. Linear evolutions were observed for the compositional dependences of density, glass transition temperature, refractive index, and photoelastic constant in visible transparent oxide glasses. The structural information was provided using vibrational spectroscopy to elucidate polyhedral units of the borate and borosilicate systems. A weak ligand field around a Sn2+ close to tetrahedral borate unit, which is supported by applying density functional theory calculation, might lead to a blueshift of optical bandgap keeping small photoelastic constant and high refractive index.

Colorless Bi₂O₃-containing borophosphate glasses with high refractivity

“…If BO 4 units were involved in the coordination in part, they would contribute to forming a weak ligand field since the net charge would be ¹3/4. 18) The fact that the coordination structure around a Bi 3+ in the 40Bi 2 O 3 -60P 2 O 5 glass resembles a BiPO 4 crystal 5), 19)…”

Effect of SnO and Bi₂O₃ on the elastic moduli of silicate glass with high refractivity and small photoelasticity

“…These glass materials contain largely polarized ions, such as Sn 2+ and Bi 3+ , with zero/small PECs, which can be used as alternatives for hazardous Pb 2+ ions in zero photoelastic glass. 5) For example, in binary silicate glass, such as SnO, 6) PbO, 5) Sb 2 O 3 , 7) and Bi 2 O 3 , 8) oxides can have different PECs with negative and positive values by changing their concentrations.…”