Structure and phase composition of BiFeO3 : La films synthesized by chemical deposition from solutions

The transmission electron microscopy, energy-dispersive, and X-ray powder diffraction analyses have been used to study the changes in the structure and phase composition of lanthanum-doped BiFeO3 and undoped BiFeO3 thin films synthesized by chemical deposition from solutions and annealed in the temperature range 500-700A degrees C. It has been found that the temperature of the onset of crystallization with formation of the rhombohedral phase of BiFeO3 is 500A degrees C. As the annealing temperature increases, the phase composition of the film is changed: the Bi3.43Fe0.57O6 and Bi2Fe4O9 phases are formed. The lanthanum doping increases the crystallization temperature to 550A degrees C; in this case, the film remains single-phase to T = 700A degrees C.