Study on optical and structural properties of lithium zinc phosphate glasses / Nurul Ain Abd Malek

Glasses with chemical composition of (60 - x)P2O5-25ZnO-(15 + x)Li2O with 0.0
≤ x ≤ 5.0 mol% are prepared by melt quenching technique. The glass properties
dependence of LhO content were investigated. The physical properties, by mean
of density and molar volume are determined. The amorphous nature, optical
absorption and structural behaviour are characterized using X-ray diffraction
(XRD), ultraviolet-visible-near infrared (UV-Vis-NIR) and Fourier Transform
Infrared (FTIR) respectively. In this work, the glass densities are found increases
in the range of 2.6991 gcm-3 to 2.7848 gcm-3 and molar volume decreases from
40.7450 gcm-3 to 37.4839 gcm-3 with respect to LhO concentration. Meanwhile,
the optical band gap by mean of their direct and indirect transition is found
ranging from 2.5253 eV to 3.0737 eV and 1.6700 eV to 2.6990 eV respectively.
The Urbach energy was found varies from 0.9594 eV to 3.4454 eV. Meanwhile,
the refractive index is found vary from 2.4833 to 2.8952. The FTIR spectra
exhibited seven bands which centered at 512 cm-I, 767 cm-I
, 918cm-l, 1087cm-I, 1281 cm-I, 1627 cm-I and 3441 cm-I wavenumber that assigned as
vibration of Zn-O, symmetric stretching vibration of P-O-P rings, asymmetric
stretching vibration of P-O-P groups, asymmetric stretching of P02- group,
asymmetric stretching vibration P=O, bending vibration of water molecule and
fundamental stretching of hydroxyl group.