Infrared Spectra of GeO 2 ‐P 4 O 10 ‐V 2 O 5 Glasses and Their Relation to Structure and Electronic Conduction

Infrared spectra of binary and ternary compositions in the glassy state and in the devitrified crystalline state in the system GeO 2 ‐P 4 O 10 ‐V 2 O 5 were studied and compared with infrared spectra of crystalline spinels, which are known to contain V 5+ ions in sixfold coordination. Results indicated that the fundamental vibration frequency of the V—O bond occurred at wave number 1015 cm −1 . The spectra also provided evidence that the V 5+ ion existed in sixfold coordination in the glassy state, as well as in the devitrified crystalline state, and that the VO 6 octahedron retained its identity even at low concentrations and melting temperatures of 1450°C. Conductivity measurements indicated that, as the concentration of V 2 O 5 decreased below the critical range of 5 to 10 mole %, there was an abrupt loss in the electronic conductivity of the glasses; the conductivity decreased with increasing concentration of the lower valence states of vanadium. A mechanism of conduction compatible with the structure of glasses in the system is suggested to explain these observations.