Preparation and ionic conductivity of transparent glass−ceramics containing a large quantity of lithium−mica

Abstract In order to crystallize a large quantity of the lithium−mica in glass−ceramics, 5.1 mass% MgF 2 was added to the starting materials of the parent glasses having chemical compositions of Li (1+ x ) Mg 3 AlSi 3(1+ x ) O 10+6.5 x F 2 ( x = 0.5 and 1.0). Transparent glass−ceramics, in which a large quantity of lithium−mica with particle size of 2 -added parent glass with x = 0.5. While the parent glass, which had a binodal phase separation structure, did not exhibit electrical conductivity, the transparent glass–ceramic was given conductivity by the formation of an interlocking structure of mica. As the separated mica formed a tighter interlocking structure, the conductivity increased and reached a value of 2.0 × 10 −3 S/cm at 600 °C. The MgF 2 -added parent glass with x = 1.0 was not transparent because of coarse spinodal phase separation. The conductivity was 4.3 × 10 −4 S/cm at 600 °C but was significantly decreased by the separation of mica.