Fe2O3 doped Lithium Sodium Bismuth Borate Glasses: Physical, Thermal, Structural and Optical Properties

Abstract

In this paper we synthesized Fe₂O₃ doped Lithium Sodium Bismuth Borate Glasses in the composition ranges xFe₂O₃-25Li₂O-5Na₂O-15Bi₂O₃-(55-x)B₂O₃ (where x = 0,2,4,6 mole%) via convenient melt quenching technique. The XRD pattern of all the glass samples confirmed the glassy nature. FTIR spectral analysis revealed the presence of BO₃ and BO₄ units, bending vibration of B-O-B linkages and Bi–O band vibrations in BiO₆ octahedral units. It has been observed that the 806 cm^-1 band was absent indicating the absence of boroxyl rings. The direct optical band gap has been computed from the optical data and found to be in the range of 0.94-1.83 eV. At x=6%, thermal characteristics such as T_g and optical properties such as direct optical band gap and refractive index showed fascinating anomalous behavior. The data was analyzed with the Arrhenius expression. DC conductivity values range from 10^-8 to 10^-6 Sm^-1 at temperatures ranging from 423K to 573K. With an increase in frequency, AC conductivity increases.