Influence of P₂O₅/TeO₂ composition ratio on the physical properties of V₂O₅–P₂O₅–TeO₂ glasses for lead-free low-temperature sealing

Abstract

We examined how the composition ratio of P 2 O 5 to TeO 2 affected the physical properties and the structure of the semiconductive vanadate glasses in a low-melting V 2 O 5 P 2 O 5 TeO 2 glass system containing 57 mol % V 2 O 5 . It was found that increasing the P 2 O 5 content and correspondingly decreasing the TeO 2 content raised the glass transition temperature and the deformation temperature as well as the fraction of the reduced V ions ([V 4+ ]/[V total ]) and the average interionic distance of the V ions. In addition, the increase in P 2 O 5 content from 7 to 32 mol % lowered the thermal expansion coefficient, volume resistivity, and density by 27, 42, and 14%, respectively, and also lowered the apparent molar volume of O ions and crystallization tendency. Furthermore, the infrared (IR) spectra suggested that the TeO 2 -enriched glasses had a layered structure similar to crystalline V 2 O 5 , whereas the P 2 O 5 -enriched glasses had a denser layered structure as a result of the increased packing density of the O ions due to the reduction of the V ions.

Synthesis and characterization of a titanium phosphate‐tellurite glass for Faraday rotators

“…TeO 2 glasses can be classified into either Te‐rich glasses with around 50 mol% TeO 2 in binary and ternary systems with application in lasers, optical fibers, amplifiers, 1‐11 or into low‐Te glasses where TeO 2 is only added in low amounts as dopant 3,12‐15 . TeO 2 glasses are promising low phonon hosts for rare‐earth elements 1,16‐23 or present luminescence properties themselves 2 .…”

Encapsulation of nitride phosphors into sintered phosphate glass by pressureless firing and hot isostatic pressing

“…The transparencies of glasses are noted, in contrast to the colored glasses having extremely low melting points, such as vanadium‐based glasses (V 2 O 5 –P 2 O 5 –TeO 2 ) and bismuth‐based glasses (Bi 2 O 3 –ZnO–B 2 O 3 –BaO). On the other hand, the enhanced T g and reduced amount of dissolution indicate that ZnO seems to play a role in the reinforcement of glass network structure, due to the incorporation of Zn 2+ as a network former into the B–O–B and P–O–P bonds.…”

Strengthening Thermal Stability in V2O5-ZnO-BaO-B2O3-M(PO3)n Glass System (M = Al, Mg) for Laser Sealing Applications

“…Among the candidate compositions, V 2 O 5 -P 2 O 5 -based glasses have been studied a lot in order to overcome the narrow glass-forming area of vanadium-based glass. It was reported that, when P 2 O 5 is added into V 2 O 5 -based glass systems, the glass formation stability is improved [9,10]. However, there is a limit to its application as a sealing glass due to poor chemical durability and low water resistance [11].…”