Observation of ~(57)Fe-Enriched BiFeO_3 Thin Films Using Moessbauer Spectroscopic Microscope

摘要

~(57)Fe-enriched BiFeO_3 (BFO) thin films were produced from a stoichiometric precursor solution by chemical solution deposition process. The perovskite BFO thin film fabricated at 550℃ on a Pt/Ti/SiO_2/Si substrate showed saturated polarization-electric field (P-E) hysteresis loops. The remanent polarization P, and the coercive field E_c at room temperature were 89μC/cm~2 and 365kV/cm, respectively. The Mossbauer spectra consisted of the antiferromagnetic perovskite BFO and a paramagnetic component at a fraction in the range of 11 to 14%. The secondary component was supposed to be due to Bi_2Fe_4O_9 and/or an amorphous component, influencing the ferroelectric property at room temperature. The Bi_2Fe_4O_9 thin film was also fabricated at 700℃ on a SiO_2/Si substrate. Furthermore, we tried to measure the mapping images corresponding to the perovskite BFO and Bi_2Fe_4O_9 components separately using a M6ssbauer spectroscopic microscope. A mapping image showed the distribution of the perovskite BFO component on the film.