Formation of a fluorite phase in SrBi₂Nb₂O₉-Li₂B₄O₇ glasses

Different compositions of (1-x)Li₂B₄O₇. xSrBi₂Nb₂O₉ (x =0.15, 0.25 and 0.35) glasses were prepared. Crystallisation processes were studied by means of thermal and structural investigations.It was found that the mixed glass produced a nano size SrBi₂Nb₂O₉ (SBN) fluorite phase in the early stages of crystallisation. This material transformed into the final crystalline phases of Li₂B₂O₄ (LBO) and layered SBN.The glass forming ability decreased with increasing SBN concentration. The activation energy for the formation of SBN fluorite phase increased with decreasing LBO content indicating that the LBO glass matrix plays a key role in SBN crystallisation.