Thermal, structural and electrical study of boron-incorporated LATP glasses and glass-ceramics

Abstract Glasses of three compositions were prepared in the Li 2 O–Al 2 O 3 –B 2 O 3 –TiO 2 –P 2 O 5 system. Next, they were heat-treated at 900 °C for 2 h to yield fast Li + ion conducting glass-ceramics of NASICON-like structure. Effects of boron additive on structural, thermal and electrical properties of glasses and glass-ceramics are herein investigated and discussed. Thermal analysis revealed that glass transition and crystallization temperatures shift towards lower values with increasing boron content. Moreover, the system under study exhibits improved glass-forming ability. X-ray diffraction studies show that B-incorporated glass-ceramics are mainly composed of rhombohedral R 3 c phase with unit cell parameters a and c decreasing with boron substitution. Raman peaks at 791 cm −1 and 1206 cm −1 in glasses with B 2 O 3 addition confirm the presence of BO 4 and BO 3 units in the glass structure. Overall ion transport properties (total conductivity and activation energy) were characterized by means of impedance spectroscopy. For optimized composition, the highest total conductivity of 6 · 10 −5  S/cm for B-incorporated glass-ceramics was recorded. Moreover, separation of the bulk and grain boundary electrical responses was performed on the basis of equivalent circuit modelling of impedance data.