Highly (00l)-textured BiFeO3 thick films integrated on stainless steel foils with an optimized piezoelectric performance

Piezoelectric BiFeO3 films were successfully prepared on 304 stainless steel (SS) foils via RF-magnetron sputtering at 450 degrees C. By adopting a LaNiO3/Pt/Ti tri-layer bottom electrode, a predominant (100)-orientation and a better crystalline morphology were achieved in the BiFeO3 film, resulting in better ferroelectric and dielectric properties targeted for piezoelectric applications than those directly grown on SS or LaNiO3/SS. These properties include a large remnant polarization (P-r similar to 68 mu C/cm(2)), a large coercive field (E-c similar to 241 kV/cm) and a sizable selfbias (E-bi similar to 158 kV/cm), as well as a low dielectric constant and a reduced dielectric loss (epsilon(r)<= 200 and tan delta <= 0.026 in 1 kHz-1 MHz). Based on this optimal BiFeO3-SS heterostructure, large converse and direct transverse piezoelectric coefficients vertical bar e(31,f)vertical bar similar to 1.7 C/m(2) and 1.07 C/m(2) were achieved in prototype piezoelectric actuator and energy harvester structures, respectively. These results suggest that BiFeO3-SS heterostructures have a great potential for applications in lead-free, metal-based piezoelectric micro-electro- mechanical systems (piezoMEMS).

Automated summary

Piezoelectric BiFeO3 films were successfully prepared on stainless steel foils and exhibited enhanced ferroelectric and dielectric properties. The optimized heterostructure achieved large piezoelectric coefficients for applications in actuators and energy harvesters.