Abstract
Glasses with compositions xMgO-(20−x)CaO-10Al2O3-20B2O3-50SiO2 (x = 0, 5, 10, 15 and 20 mol%) were prepared by conventional melting method. X-ray photoelectron spectroscopy (XPS) results indicated that the proportion of non-bridging oxygen increased with increasing MgO content. Nuclear magnetic resonance spectra showed that the fraction of the four-coordinated boron ions N4(B) and aluminum ions N4(Al) decreased with increasing MgO/CaO. Thus, higher field strength cations were expected to weaken the glass network. However, the increase in the glass transition temperature (Tg) indicated that the magnesium ions strengthened the glass network. The decrease in dielectric constant er and loss tanδ could be attributed to the increase in the rigidity of the glass network as the MgO content increased.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
