Ferroelectric characteristics of oriented Pb(Zr_1-xTi_x)O₃ films

Pb_1.2Zr_1-xTi_x)O₃ (PZT) films with a variety of compositions were prepared by spin coating on Pt/Ti/SiO₂/Si substrate with sol-gel processing. The roles of composition (phase) and orientation in ferroelectric properties of PZT films have been determined. The Zr-rich PZT films with (111)-oriented PZT films have a higher remanent polarization but also show a higher fatigue rate as compared to (100)-oriented films in both Zr-rich(65/35) and Ti-rich(35/65) PZT compositions. The lower fatigue rate of (100)-oriented film can be attributed to its easier reversible domain-wall motions compared to (111)-oriented PZT films due to the absence of internal field stress and less dependence on electrical field. A mode based on domain-wall contribution instead of film-electrode interface is favored to elucidate the role of orientation in fatigue characteristics of PZT films.