Crystal orientation dependency of ferroelectric property in rhombohedral Pb(Zr,Ti)O₃ films

Abstract

Ferroelectric properties were investigated for (100), (110), and (111)-single-oriented rhombohedral Pb(Zr0.65Ti0.35)O3 films. Saturation polarization, P sat, was changed by the simple tilting angle of the polar axis from the film surface normal. On the other hand, (100)- and -oriented films prepared on (100) Si substrates showed similar P sat values due to the coexistence of orientation. The coercive field, E c, of rhombohedral Pb(Zr0.65Ti0.35)O3 films was lower than that of tetragonal Pb(Zr0.4Ti0.6)O3 films. (100)-oriented rhombohedral films with SrRuO3 electrodes did not show noticeable degradation in polarization up to 1010 switching cycles. These results show that (100)-oriented rhombohedral Pb(Zr x Ti1− x )O3 film is available to realize the low voltage operated ferroelectric random access memory instead of the present tetragonal Pb(Zr x Ti1− x )O3 films.