Process-dependent Coercive Fields in Undoped and Mn-doped BiFeO3 Films Formed on SrRuO3/Pt(111) Electrodes by rf Sputtering

We deposited BiFeO3 (BFO) thin films on SrRuO3 (SRO)/Pt bottom electrodes by radio-frequency (RF) sputtering. Some samples were formed at the substrate temperature of 550°C, and others were formed at 450°C and post-annealed at 650°C for crystallization. The coercive field in the post-annealed BFO film was smaller than that in the 550°C-deposited BFO film. The coercive field in Mn-doped BiFeO3 (BFMO) films which were deposited at 550°C on SRO/Pt (111) was lower than that in undoped BFO films. Degradation of the remanent polarization was less significant in the post-annealed BFO film.