Phase transition in barium titanate nanocrystals by chemical treatment

Effects of solvents on the cubic to tetragonal phase transition of barium titanate (BT) nanocrystals were investigated by solvothermal treatment. Different processing variables, such as temperature and time were taken into consideration for different solvents. There were no effects on the phase transition of BT below the boiling temperature of all the solvents. Above the boiling temperature, a nanocrystals of tetragonal barium titanate could be obtained from the commercial cubic phase BT powder (Cabot, BT-08). There were no significant changes of the particle size and morphology of the BT powders before and after the chemical treatment. There was small reduction of surface area and particle size observed in the chemically treated BT powders. The crystal structure, phase transition and morphology of the powders were analyzed by XRD, DLS, DSC, TGA and SEM.