EPR AND MAGNETIC SUSCEPTIBILITY STUDIES OF Gd3+ IONS-DOPED BISMUTH–GERMANATE GLASS MATRIX

Abstract

Glasses of the x Gd 2 O 3 · (100-x)[4 Bi 2 O 3 · GeO 2] system, with 1 ≤ x ≤ 30 mol% were obtained and investigated by electron paramagnetic resonance (EPR) and magnetic susceptibility measurements. The EPR spectra of the studied glasses reveal resonance sites with an unexpected high crystalline field in addition to the "U" spectrum, typical for Gd 3+ ions in glasses. This absorption line is due to Gd 3+ ions that replace Bi 3+ ions from the host glass matrix and can play former role of the unconventional network in the studied glasses. EPR and magnetic susceptibility data show that for low Gd 2 O 3 content, x ≤ 10 mol%, the Gd 3+ ions are randomly distributed in the host glass matrix and are present only as isolated species. For higher Gd 2 O 3 content, x > 10 mol%, the Gd 3+ ions appear as both isolated and antiferromagnetically coupled species.