Infra-red study of polymerisation in silver, thallium, and thallium aluminogermanate glasses

Abstract

The infra-red spectra of silver germanate, thallium germanate, and thallium aluminogermanate glasses are presented for the 1100 cm⁻¹ to 400 cm⁻¹ region. The pseudo rare gas type Tl⁺ and Ag⁺ ions produce spectral shifts in binary germanate glasses that are similar to those reported for alkali ions. Differences for Tl⁺ may be due to its high atomic weight and polarising power. The infra-red spectral shifts observed for thallium aluminogermanate glasses are those expected if GeO₆ octahedra disappear while AlO₄ tetrahedra engage in network repair. A structurally sensitive technique for displaying ternary oxide glass infra-red spectra is outlined. This technique is capable of discerning different modes of network depolymerisation and polymerisation in ternary germanate and silicate glasses.