EPR AND MAGNETIC INVESTIGATIONS OF CHROMIUM IONS IN TeO2 BASED GLASSES

Electron paramagnetic resonance (EPR) and magnetic susceptibility measurements on xCr2O3 ⋅ (100-x)[70TeO2 20B2O3 5MO] glasses with MO PbO, SrO, SrF2 and 0 < x ≤ 20%mol are performed. The EPR spectra due to the Cr3+ ions in vitreous matrix revealed the structural details of the diamagnetic host, the coordination and the distribution of these ions, the EPR parameters being sensitive to the local symmetry, the character of the chemical bonds as well as of the structural factors. EPR and magnetic susceptibility data have shown that the Cr3+ ions are present in the studied glasses as isolated species, coupled by dipol-dipol and/or negative superexchange interactions. The strength of these interactions was determined in function of x and different modifiers of vitreous matrix