Studies on lithium alumino phosphate glasses doped with selenium ions for hard electrolytes

Abstract

Glass samples of the system (100 -x) (0.5 Li 2 O-0.2Al 2 O 3 -0.3P 2 O 5 ) ? xSeO 2 (x is ranging from 0 to 12 mol%, labeled as LAPS x ) were prepared using the melt quenching technique. FTIR spectral studies indicate that selenium ions mostly occupy network modifying sites due to isolated selenite (SeO 3 2-) groups up to 6 mol% of SeO 2 (LAPS 6 ) in the LAPS glass network. This has a tremendous effect on the electrical properties. Glass forming ability parameter (K gl ) and the glass transition temperature (T g ) of LAPS samples were characterized by DTA traces. Electrical measurements were carried out as a function of frequency and temperature over the frequency range of 10 Hz to 10 6 Hz and a temperature range of 303-423 K. The electric modulus formalism was applied to study the relaxation behavior using the impedance data for all the samples at 303 K and also for analyzing the relaxation behavior of the highest conducting sample (6 mol% of SeO 2 ) at different temperatures. An attempt has been made to relate the measured properties to the structural modifications due to the modifying effect of isolated selenite (SeO 3 2-) groups in the glass network.