Impact of copper oxide on the structural, optical, and dielectric properties of sodium borophosphate glass

Abstract

Sodium borophosphate glasses containing copper oxide (CuO) have produced by melt annealing technique. Phosphate units are presented in Q2, whereas the borate groups are presented as trigonal and tetraborate units. The addition of CuO in the network former modifies the characteristic mid region of infrared bands or peaks. The base glass sample has a density of 2.57 g/cm3 raising to 2.71 g/cm3 after doping with 0.1 CuO. The absorption edges of such glass shifted towards lower photon energy due to the formation of non-bridging oxygens (NBOs). With the increase in the copper content from 0 to 0.1 mole fraction, the optical transition values decreased from 3.682 to 1.672 eV. The real and imaginary part of dielectric constants decreased as the applied frequency increase due to the dipolar, interfacial, and dielectric polarization effects. The relaxation process has observed at high frequency and 0.1 CuO sample correlated to the formation of NBOs.