“…The T c and D increase as the z=r (or z=r 2 ) of the modifying cation increases [7]. Based on Debye-Huckel theory, by taking the degree of dissociation of cations in glass into account [4,9], a single master curve of T c versus z=ae (a ¼ distance between glass forming cation, tetrahedrally coordinated Si or B, and the nearest neighbor network modifying cation, and e ¼ dielectric constant) was demonstrated to exist for both silicate [9] and borate [10] systems exhibiting phase separation. This result supports the conclusion that phase separation originates from ionic interactions.…”