AN ESR STUDY OF PURE AND VANADIUM-DOPED GEXS100-X GLASSES

Pure and vanadium-doped glasses of the formula GexVyS100-x-y (x less-t han-or-equal-to 33.33, y less-than-or-equal-to 0.15) were prepared. Th e electron spin resonance (ESR) spectrum is single-line for pure GeS2 and multi-line for S-rich glasses. A signal with hyperfine splitting ( HFS) which can be assigned to V4+ in the perturbed octahedral ligand f ield of sulphur atoms was found in glasses with 33.33 at.% Ge but not in S-rich glasses. The natures of the ESR active defect centres in pur e and V-doped glasses are discussed.