Enhanced Piezoelectric Properties of Epitaxial W-Doped BiFeO3 Thin Films

BiFeO3 and BiFe1-xWxO3 (x = 0.005, 0.01, 0.02) films were epitaxially deposited on LaNiO3(100)/Si substrates using a metal organic decomposition process. Well-saturated polarization–electric field hysteresis loops can be observed in all BiFe1-xWxO3 films owing to their leakage currents being lower than that of the BiFeO3 film. Additionally, the domains in BiFe0.995W0.005O3 and BiFe0.99W0.01O3 films can be uniformly switched using a piezoelectric-mode atomic force microscope (AFM) due to the efficient deaging effect of W6+. More importantly, the BiFe0.99W0.01O3 film exhibits the highest piezoelectric coefficient (~132 pm/V) among all the films, making it promising for applications in high-temperature piezoelectric devices and AFM-tip-based data storage.