LAUSR

Abstract UV absorption spectra of quaternary tellurite glasses in the form TeO2-WO3-Li2O-Nb2O5/Sm2O3/Pr6O11/Er2O3 were measured in the range 200–850 nm. Optical energy gap EASFopt. (eV), EDASFopt. (eV), Urbach's energy Eu (eV), and refractive index (n) were calculated using both absorption spectrum fitting (ASF) and derivation of absorption spectrum fitting (DASF) methods. Room temperature electric measurements were carried out by using LCR Hi Tester Meter Bridge in the frequency range of 100 Hz-100 kHz. Dielectric constant, e′, dielectric loss, e″, and ac conductivity, σac, have been found. Results show that, in ASF method the optical energy gap values are in the range of 3.59 to 4.58 and 4.76 to 5.18 eV for indirect and indirect transition, respectively, while in DASf method, the optical energy gap values are in 5.14 to 5.30 eV. Refractive index values for glass systems are in the range of 2.06 to 2.25 and 1.973 to 2.254 for indirect and indirect transition, respectively in ASF method, while in DASF method it takes values from 1.95 to 1.97. Electrical data e′, e″ and σac of the present glasses were in the range 18,611.9 to 24,670.9 ± 0.25, 2070.4 to 2842.8 ± 0.15 at (100 Hz) and 4.50 to 6.26 ± 0.05 × 10−4 (Ω·cm)−1 (100 kHz), respectively.