Abstract
The addition of 
, 
, or 
to glass A with composition (weight percent [w/o]) 
resulted in more negative surface charge density and increase in the thermal expansion coefficient (α). The glass B, 
showed finer crystals by the addition of 
(1 w/o) or glass A without affecting the surface charge density or α. The effects of additives on the DTA characteristic temperatures of the two glasses are also presented.