Spectroscopic and magnetic behaviour of xGd 2O 3 (1 − x)(Bi 2O 3·PbO) glasses

Abstract

Glasses of the xGd 2O 3 (1 − x)(Bi 2O 3·PbO) system (0 ≤ x ≤ 0.15) were obtained and studied by IR spectroscopy, electron paramagnetic resonance (EPR), magnetic susceptibility and density measurements. IR data show that increasing the amount of gadolinium ions in the studied glasses produces structural modifications of the host vitreous matrix consisting in a conversion of the [BiO 3] into [BiO 6] structural units. EPR and magnetic susceptibility data show that for low gadolinium oxide content of the samples, x ≤ 0.05, the Gd 3+ ions are randomly distributed in the host glass matrix and are present only as isolated species. For higher gadolinium oxide contents of the samples, x > 0.05, the Gd 3+ ions appear as both isolated and antiferromagnetically coupled species. IR and density measurements support the assumption of the network modifier role played by the gadolinium ions in the xGd 2O 3 (1 − x)(Bi 2O 3·PbO) glasses. EPR data show an unusual absorption line for the Gd 3+ ions in glass matrices. This absorption line is due to Gd 3+ ions that replace Bi 3+ and Pb 4+ ions from the host glass matrix and play the network former role in the studied glasses.