Influence of texture on the switching behavior of Pb(Zr_0.70Ti_0.30)O₃ sol-gel derived thin films

Abstract

Rhombohedral Pb(Zr 0.70 Ti 0.30 )O 3 thin films of four different well-defined textures, namely, (100), (111), bimodal (110)͞(111), and (100)͞(111), were prepared by a sol-gel method. The films were characterized in terms of grain size, presence of second phases, surface roughness, columnarity of grains, and other microstructural features. The dielectric, ferroelectric, and fatigue properties were investigated, with emphasis on the hysteresis switching characteristics. Results are discussed from the reference point of the allowable spontaneous polarization directions available for the different textures. The values of coercive field, remanent and saturation polarization, and slope of the loop at the coercive field, at saturating fields can be qualitatively explained based on the texture, independent of microstructural differences. The occurrence of surface pyrochlore, however, is observed to affect the functionality of the saturation curves, particularly for the samples of bimodal texture. Shearing of the hysteresis curves of the bimodal films is also attributed to surface microstructural features. The occurrence of nonswitching 71± or 109 ± domains in the (111) and (110)

Growth and electrical properties of Pb(Zr,Ti)O3 thin films by a chemical solution deposition method using zirconyl heptanoate as zirconium source

“…The 180 domains, normal to the film surface, mainly contribute to the polarization, whereas 90 domains, parallel to the film surface, which are difficult to reorient, contribute to the polarization only under a larger applied field [22][23][24]. Domain switching is strongly dependent on the applied field and film orientation.…”