Synthesis, structural, optical properties and dielectric spectroscopy of nickel-doped lead borate glasses

The influence of nickel-oxide (NiO) addition on the structural, optical, physical properties, and dielectric spectroscopy of lead-borated glass blocks of the chemical form: (70-x)B2O3-25Na2O-5PbO-xNiO: x = 0 (Ni-0.0)-2.5 (Ni-2.5) molar percentage was tested experimentally using various methods. X-ray diffraction measurements confirmed the amorphous character of prepared Ni-glasses. Density increased gradually from 2.5981 to 2.7568 g cm-3, whereas molar-volume declined from 29.0131 to 28.0202 cm3 mol-1 as Ni2+ ions-contenting samples improved from 0.0 to 2.5 mol% in glasses network. In the absorption UV-region, optical-gap energy changed between 2.94 and 2.48 eV. In absorption within Vis-region, the intensity of the absorbed band enhanced gradually with red-shift in their positions as Ni2+ ions content increased. In the absorption NIR-region, an increase in the IR absorption bands was observed and confirmed the enhanced heat-absorption capacity of the investigated glasses as their NiO content increased. Dielectric spectroscopy at frequencies ranging from 50 Hz to 5 MHz of (70-x)B2O3-25Na2O-5PbO-xNiO: x = 0, 0.5, 1.0, 1.5, 2.0, and 2.5 mol% glasses are carried out to determine the impact of nickel doping on dielectric spectroscopy items. Nickel doping gradually increased the dielectric constant. At high frequencies, the transport rate among nearby conductive sites is increased while the shifting length of the charges is greatly reduced which leads to higher conductivity.