Address of SiO2-based addtives in Bi4Ti3O12 thin films

By the crystallographic analysis of BIT, BIT-0.05Bi(2)O(3) .SiO2 , and BIT-0.10Bi(2)O(3) .SiO2 powders, the SiO2-based additives were found to work as a buffer for the Bi composition of BIT; the excess Bi2O3 was incorporated into non-crystalline SiO2 rather than BIT. Thereby, the excess Bi2O3 was suppressed and the stoichiometry in BIT was compensated. In the thin films, the number of nucleation sites, which were at the edge of the amorphous phase, decreased with increasing the additives. The development of dense and fine texture was resulted in the 500degreesC-crystallized BIT-0.05Bi(2)O(3) .SiO2 and BIT-0.10Bi(2)O(3) .SiO2 thin films. While the 40 nm-thick BIT films were electrically shortened, the BIT-0.05Bi(2)O(3) .SiO2 and BIT-0.10Bi(2)O(3) .SiO2 thin films improved electrical properties and exhibited unique ferroelectric behaviors. The SiO2-based additives pinned the leak current path.