Enhanced piezoelectricity and energy storage performances of Fe-doped BNT–BKT–ST thin films

Fe-doping is an effective way to improve physical performances of piezoelectric and ferroelectric materials. Under such circumstances, x mol% (x = 0.0, 1.0, 1.5, 2.5) Fe-doped 0.72Bi0.5Na0.5TiO3–0.18Bi0.5K0.5TiO3–0.10SrTiO3 (BNT–BKT–ST–xFe) thin films were prepared by sol-gel method and the relationships between the content of Fe and electromechanical properties of the films were studied. The BNT–BKT–ST–1.0Fe thin films exhibit the best electromechanical properties, whose Smax/Emax, Wrec, η, Pmax, Prem and εr of are 68.00 pm/V, 20.34 J/cm3, 65.17%, 71.5 μC/cm2, 14.8 μC/cm2, 868 respectively. These results indicate that BNT–BKT–ST–1.0Fe thin films are promising for applications for advanced piezoelectric materials and capacitors with high energy-storage density.