Physical and Optical Characterization of Manganese Ions in Sodium-Zinc -Phosphate Glass Matrix

Abstract

In order to investigate the significant modifications induced by incorporation of manganese ions in sodiumzinc-phosphate glass matrix, a glass system of chemical formula 40P 2 O 5-40ZnO-(20-x)Na 2 O-xMnO (where, x varied from 1 to 6 mol%) was prepared using the traditional melt quenching technique. The values of the glass density were increased and those of the molar volume were decreased by increasing the content of MnO. In addition, the concentration of manganese ions and the related field strength were increased while the corresponding inter-ionic spacing and polaron radius were decreased. The spectroscopic studies of all samples were carried out over (190-2500 nm) spectral range. The optical transmission of the prepared glass in the visible-near IR spectral range is enhanced by increasing the MnO content where it reaches a maximum value of about 86% at concentration 3% of MnO. This excellent transmission in such spectral range suggested the use of the present glass in many technological applications such as optical filters, IR domes, modulators, laser windows and lenses especially for Nd:YAG lasers. The optical band gap energy and the Urbach energy were determined. The refractive index was found to be decreased by increasing the MnO concentration from 1% to 3% then increased by increasing the MnO concentration from 3% to 6%. Other related physical parameters such as dielectric constant, electric susceptibility, molar polarizibility and metallization criterion were evaluated. The results predicted the working of the present glass in the range of nonlinear optical materials.

Structural and Calorimetric Studies of Zinc, Magnesium and Manganese Based Phosphate and Phosphate-Silicate Glasses

“…Nevertheless, phosphate-based glasses containing transition metal ions are scientifically interesting materials due to their attractive properties which can be used in many technological applications including electronic and electro-optical devices [21].…”

“…In fact, transition metal oxides can be dissolved easily in phosphate glasses which exhibit one than more oxidation sates [21,25,30].…”

“…Contrary to Zn 2+ and Mg 2+ ions presented in one oxidation state, spectralluminescent properties of manganese ions in phosphate glasses allow them to be good candidates for interesting optical applications [21,25,30].…”

“…In borate glasses, manganese exists mainly as Mn 3+ ions with octahedral coordination in glass networks whereas in silicate and germinate glasses, it identified as Mn 2+ ions with both tetrahedral and octahedral coordination [21].…”

“…The addition of transition metal oxides (CuO, MgO, ZnO, MnO, CaO…) into the vitreous network (TMO) disrupted the P▬O▬P bridges leading to the structure depolymerization and the formation of non-bridging oxygen atoms (NBO) [2,5,6,8,9,13,21,25,32,35]. Which induces the formation of P▬O▬M bonds replacing the easily hydrosoluble P▬O▬P bridge that improve the chemical durability of the phosphate network [21].…”