Effects of cation field strength on structure and properties of boroaluminosilicate glasses

Abstract

Among the most important adjustable compositional variables in controlling glass and glass melt properties were the relative proportions of network modifiers with varying cation field strength (ratio of charge/radius). In alkaline earth boroaluminosilicate glasses RO–B₂O₃–Al₂O₃–SiO₂ (R = Mg, Ca, Sr, Ba), the changes of structure and properties caused by variations in the ratio RO/BaO were investigated. The structural role of RO was investigated by Fourier transform infrared spectroscopy and nuclear magnetic resonance. Chemical durability was evaluated by weight losses of glass samples after immersion in HCl and NaOH solutions. High resolution scanning electron microscopy was used to examine the surface micrographs of corroded glass samples. The dielectric constant and tangent loss were measured at 1 MHz. The results indicated that the fraction of four-coordinated boron atoms (N4), chemical durability and dielectric properties increased in the order Mg>Ca>Sr>Ba.

Keywords:

• Boroaluminosilicate glasses
• Alkaline earth cations
• Cation field strength
• Structure
• Chemical durability
• Dielectric properties

Acknowledgements

This work was supported by Natural Science Youth Foundation of Shandong Province (grant no. ZR2011EMQ005), Natural Science Foundation of Shandong Province (grant no. ZR2012EMM019) and National Natural Science Foundation (grant nos. 51172093, 51042009).