Dielectric and spectroscopic investigations on zinc arsenate glasses with Bi2O3 as additive

(50-X) ZnO-50 As2O3-X Bi2O3 (5 ≤ X ≤ 30 with the increment of 5 mol %) glasses were synthesized by melt quenching with subsequent annealing. The prepared glasses were characterized by X-ray diffraction, which confirmed the glassy nature of the samples. Spectroscopic studies viz., optical absorption, FTIR and dielectric studies were carried out. Optical absorption spectra revealed the progressive increase of NBO is with the increase of Bi2O3 concentration. From FTIR spectra it is evident that at lower concentrations of Bi2O3 Bi3+ ions enter into the glass network by forming BiO3 pyramidal structures in conjunction with tetrahedral ZnO4 where as octahedral BiO6 structural units predominate with the increase of Bi2O3 content. The dielectric parameters like ε′, tan δ and σac are found to increase with the increase of Bi2O3 concentration while a fall of activation energy for conduction is noticed. The correlation between the above said studies suggests that the glasses are more rigid at lower concentrations of Bi2O3 and conductivity of the glasses is observed to increase at higher concentrations of Bi2O3 due to increase of BiO6 and ZnO6 structural units. Hence, C1 sample (45 ZnO-50 As2O3- 5 Bi2O3) is found more rigid and highly insulating glass.