Crystallization and characterization of Pb2Nb2O7 thin films prepared at high pressure and low temperature

A facile thin film crystallization of pyrochlore Pb2Nb2O7 at low temperatures has been demonstrated at high pressures over rapid thermal annealing process (RTA). The crystallization of Pb2Nb2O7 has started at temperatures as low as 220 °C. Powder X-ray diffraction patterns reveal the formation of pyrochlore phase without any intermediate phase formation. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) features show the temperature dependence of crystal growth in both high pressure and RTA methods. Using the high-pressure method, the crystallization temperatures of Pb2Nb2O7 are reduced to 220 °C when compared to 600 °C required for crystallization using RTA process. The uniform and dense structure that consisted of small grains with the size of 20–30 nm existed in the Pb2Nb2O7 thin films heated by RTA process, whereas the use of high pressure modified the crystallize size to approximately 40–45 nm with island structures observed throughout the Pb2Nb2O7 films.