[38] Polarization switching characteristics of BiFeO₃ thin films epitaxially grown on Pt/MgO at a low temperature

An [001]-oriented BiFeO₃ (BFO) thin film having a pseudotetragonal symmetry was epitaxially grown on a Pt/MgO (001) substrate. The Pt-buffered MgO substrate enabled us to fabricate an epitaxial heterostructure at a temperature as low as 500°C. We examined three major criteria for high-density ferroelectric memories using this BFO/Pt film capacitor. The polarization switching experiment has demonstrated that the film is electrically fatigue-free and possesses stable charge-retention characteristics with a reasonably large sensing margin of 22𝜇C/cm². These suggest potential applicability of the present BFO/Pt heteroepitaxial film capacitor to nonvolatile memories.