Physical, optical and structural studies of copper-doped lead oxychloro borate glasses

Abstract

Bluish coloured glasses are obtained from the composition PbCl 2-PbO-B 2 O 3 doped with Cu 2+ ions. Basic physical properties and spectroscopic studies (optical absorption, electron paramagnetic resonance, Fourier transform infrared and Raman spectroscopies) were carried out on these samples. The increase in PbCl 2 content resulted in the decrease in density and increase in molar volume. At optical frequencies, band gaps and Urbach energies were evaluated and their variation is explained. Spin-Hamiltonian parameters (SHP) obtained from the EPR spectra suggest that the ligand environment around Cu 2+ is tetragonally distorted octahedral sites and the orbital d x 2 −y 2 is the ground state. The characteristics broad bands in the optical absorption spectra are assigned to the 2 B 1g → 2 B 2g transition. The bonding coefficient values were evaluated using optical data and SHP. FTIR studies suggested that the glass structure is built up of BO 3 and BO 4 units. The presence of diborate, pyroborate, pentaborate groups, etc. in the glass network was confirmed from Raman spectra.

Effect of metal fluorides on chromium ions doped bismuth borate glasses for optical applications

“…Density plays an important role in understanding the modification of BO 3 into four fold BO 4 units, and vice versa. [1,[34][35][36] In the present study, it was found that the density decreases from 5.236 gm/cc (CZBBCR1) to 4.819 gm/cc (CZBBCR5) with increasing CaF 2 concentration. The molar volume (V m ) was estimated from density and the molecular weight (M) of the glass sample.…”

“…From previous literature, the variation in density is explained using the physical parameters like crystal density, molecular weight and/or ionic radius. [1,34,[37][38][39] The gradual enhancement in the mole percentage of CaF 2 in the CZB-BCR glass system caused a nonlinear decrease in the density, which is suitably explained using the crystal density of calcium fluoride (3.18 gm/cc) which is lesser than zinc fluoride (4.95 gm/cc). It can also be assigned to fractional replacement of low molecular weight CaF 2 (78.07 g/mol) by the high molecular weight ZnF 2 (103.406 g/mol).…”

“…[18,62,63] Another band ∼ 960 cm arise due to the asymmetric stretching of the B-O bonds in BO 3 units. [1,18,[64][65][66][67]…”

“…Our interest in borate glasses is due to its low cost, low melting temperature, wide range of composition, glass forming ability with most of the elements besides its promising applications. [1][2][3][4][5] In contrast to the oxide-based glasses, fluoride glasses have many advantages such as wide transmission window, low phonon energy, low OH contents, large solubility for rare-earth ions, wide transmission range, and long fluorescence lifetime. [6][7][8][9][10][11] From the literature it is evident that pure Bi 2 O 3 glass cannot be obtained.…”

A comparable study of the EPR spectra and local structures for 3d1‐ and 3d9‐doped halo‐borate glasses

“…In order to understand the role of TM ions in glasses, a powerful technique that characterizes specific physical natures which are sensitive to the local environments can be realized through electron paramagnetic resonance (EPR) spectra, which reveal the microscopic local environment of TM ions in glasses, including the network, symmetries, and bonding conditions around TM ions. 10,14 It is worth mentioning that EPR has been proved highly sensitive to the paramagnetic signals of these TM impurities, which has been adopted to investigate the PbX 2 -PbO-B 2 O 3 glasses (X = F, Cl, and Br) doped with Cu 2+ (3d 9 ), 7,15 represented by the properties of g factors and hyperfine structure parameters, that is, g // > g ⊥ and A // > A ⊥ for Cu 2+ . Despite the investigation of PbCl 2 -PbO-B 2 O 3 -CuO glasses in the previous article 16 and the rough explanation based on simple g formulae with various adjustable molecular orbital coefficients α 2 , β 2 , and β 1 2 , 12,13 the local structural information of paramagnetic impurities Cu 2+ in PbX 2 -PbO-B 2 O 3 glasses (X = F and Br) need to be further studied, which is helpful to acknowledge the role for different TM dopants (Cu 2+ and V 4+ ) by united and compared study.…”