Combined effect of preferential orientation and Zr/Ti atomic ratio on electrical properties of Pb(ZrxTi1−x)O3 thin films

Abstract

Lead zirconate titanate [Pb(ZrxTi1−x)O3, PZT] thin films with various compositions, whose Zr/Ti ratio were varied as 40/60, 48/52, 47/53, and 60/40, were deposited on Pt(111)/Ti/SiO2/Si substrates by sol-gel method. A seeding layer was introduced between the PZT layer and the bottom electrode to control the texture of overlaid PZT thin films. A single perovskite PZT thin film with absolute (100) texture was obtained, when lead oxide was used as the seeding crystal, whereas titanium dioxide resulted in highly [111]-oriented PZT films. The dielectric and ferroelectric properties of PZT films with different preferential orientations were evaluated systemically as a function of composition. The maximums of relative dielectric constant were obtained in the morphotropic phase boundary region for both (100)- and (111)-textured PZT films. The ferroelectric properties also greatly depend on films’ texture and composition. The intrinsic and extrinsic contributions to dielectric and ferroelectric properties were discussed.