Vibrational, EPR and optical spectroscopy of the Cu 2+ doped glasses with (90–x)TeO 2–10GeO 2–xWO 3 (7.5 ≤ x ≤ 30) composition

Abstract

Infrared, EPR and optical absorption studies on (90–x)TeO 2–10GeO 2–xWO 3 (7.5 ≤ x ≤ 30) glasses containing Cu 2+ spin probe have been carried out. The Infrared spectral studies show that the structure of glass network consists of [TeO 4], [TeO 3]/[TeO 3 + 1 ], [WO 4], [WO 6] and [GeO 6] units in the disordered manner. Physical parameters such as density (ρ), molar volume (V m), oxygen packing density (OPD), oxygen molar volume (V o), optical basicity (Λ), oxide ion polarizability ( α O 2− ), inter ionic distances and the concentration of ions per unit volume of Te, Ge, W, Cu and O have been determined. The spin-Hamiltonian parameters (g ||, g ⊥ and A ||) of Cu 2+ ions in the present glasses have been estimated from EPR spectra at 300 K. Bonding parameters such as α 2, β 1 2, β 2, Γ σ, and Γ π have been calculated from both optical absorption and EPR data. The observed variations in spin-Hamiltonian parameters and bonding parameters have been correlated to the structural modifications due to the WO 3 incorporation into the TeO 2 glass network at constant 10 mol% GeO 2 content.