Mixed cation effect in xNa2O.(1–x)Ag2O.3B2O3 glasses: a structural and dielectric investigation
Structural and dielectric properties of mixed cation Ag–Na triborate glasses were investigated by infrared and impedance spectroscopies. The short range order structure of the borate network was found to exhibit a nonlinear variation on cation mixing and this was expressed in terms of the BØ4
−BØ2O− isomerisation reaction (Ø denotes an oxygen atom bridging two boron centres). Far infrared analysis indicated the existence of dissimilar cations in neighbouring sites and cation site interactions varying with composition. The measured σdc and activation energy, E
a, were found to exhibit the typical nonlinear behaviour upon mixing. The Kohlrausch–Williams–Watts (KWW) formalism was used to describe the modulus, M″(ω), spectra and the β exponent was found to increase with increasing temperature and Na2O content. The decoupling index at T
g was also obtained and showed a negative deviation from additivity upon cation mixing.
Document Type: Research Article
Affiliations: Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vass. Constantinou Ave., Athens 116 35, Greece
Publication date: October 1, 2000
- Access Key
- Free content
- Partial Free content
- New content
- Open access content
- Partial Open access content
- Subscribed content
- Partial Subscribed content
- Free trial content