Influence of glass network ionicity on the mixed‐alkali effect

• DOI: 10.1111/ijag.15546
• Publication Date: 2020-04-28T06:27:31Z
• Authors: Courtney Calahoo; Yang Xia; Ru Zhou
• Keywords: Slippage

Abstract Most studies of the mixed‐alkali effect (MAE) have focused on relating differences between cations to strength MAE; here we examine glass former by comparing MAE in aluminofluorophosphate (FP) and aluminosulfofluorophosphate (FPS) glasses. The sulfate anion FPS series does not bond directly aluminophosphate network, decreasing connectivity increasing ionicity increased degrees freedom imparted are evident single‐alkali glasses, which lower E a , hardness, shear moduli, Young's higher T g than corresponding FP glasses (without sulfate). Conversely, for compositions, sulfate's mobility is reduced mixed cations, resulting magnified series. For dynamic properties, this phenomenon explained plasticity slippage along ion channels, while understanding elastic properties requires examination shape potential energy well regions compressive tensile stress. We posit that compositions with plasticity, is, less covalent bonding, will exhibit larger MAE, but, simultaneously, sufficient conventional network must be present constrain mobile ions.