BiFeO3 thin films prepared using metalorganic chemical vapor deposition

BiFeO3 thin films were grown on (001) SrTiO3 and (001) ZrO2(Y2O3) substrates by single source metalorganic chemical vapor deposition in the temperature range T = 500 ÷ 800 °C using Fe(thd)3 and Bi(C6H5)3 as volatile precursors. X-ray diffraction analysis shows cube-on-cube epitaxial growth of BiFeO3 on (001) SrTiO3. The strongly reduced bismuth transfer into the film due to the high thermal stability of Bi(C6H5)3 was counterbalanced by the increase of the total pressure as well as of the residence time of the precursor flow in the reactor; the Bi/Fe ratio in the film thus becomes close to that in the precursor mixture. Optical second harmonic generation measurements have evidenced the ferroelectric ordering in BiFeO3 films and the apparent decrease of the Curie temperature of the strained films as compared to BiFeO3 single crystal.