Poling effect on microstructure properties of Barium Strontium Titanate thin films

Barium Strontium Titanate (BST) is a polarizable ferroelectric material that has been used in various electronic applications. The structure of the ferroelectric grains can be reorientated by applying an external high voltage during baking or annealing process. Barium Strontium Titanate with a Ba:Sr ratio of 80:20 has been prepared using a sol-gel technique. A low baking temperature at 200°C has been used during the poling process. An external electric field 3.44 kV/mm is applied. Poled and un-poled samples are analyzed via XRD, AFM and SEM. XRD analysis shows the Ba0.8Sr0.2TiO3 crystallized with a tetragonal structure. The grain size and structure for the poled and un-poled samples of BST are different due to the effect of external electric field. The grain size of the poled sample is bigger compared to the un-poled sample.