AC conductivity and dielectric relaxation of Se80–xTe20Bix (x=6, 12) glasses
The present paper reports the ac conductivity and dielectric relaxation of Se80–xTe20Bix (x=6, 12) glasses at various temperatures and frequencies. It was found that ac conductivity increases on increase of frequency, temperature as well as Bi
content. The increase in conductivity is due to the formation of lower energy Se–Bi and Te–Bi bonds which takes the system to a stable lower energy configuration. The values of frequency exponent (s) were calculated and it was found that samples obey CBH model of conduction. Density
of states (N(Ef)) near the fermi level were calculated at different temperatures and it was found that addition of Bi increases the number of localised states in the tails which leads to increase in ac conductivity. Further, it was found that dielectric parameters increase with
increase in temperature. However, a decrease in both dielectric constant (ɛ′) and dielectric loss ((ε″) was observed with increase in frequency. Beside this, dielectric relaxation time (τ) and activation energy of relaxation (ΔEτ) were also determined
for both the samples under study and was found to be lower for Se68Te20Bi12 glass.
Document Type: Research Article
Publication date: 01 December 2019
- Access Key
- Free content
- Partial Free content
- New content
- Open access content
- Partial Open access content
- Subscribed content
- Partial Subscribed content
- Free trial content