Papers by Keyword: Ferroelectric Domain

Abstract: The switching current of the PZT domain patterns was detected by the conductive atomic force microscopy. The impact of the scan rate on the current contrast was studied. Successive current images of domain evolution during the polarization switching process were obtained. The impact of the local force exerted by the tip and the polarization cycles of the patterns were studied. The results suggested that the compressive strain exerted by the tip can decrease the piezoelectric coercive field and the polarization fatigue can increase the piezoelectric coercive field in the polarization inversion process from bottom to top.

Abstract: BiFeO₃ is a very promising multiferroic materials, which can present ferroelectric and antiferromagnetic properties at room temperature (T_n=643 K, T_c= 1103 K). Ferroelectric domains in BiFeO₃ thin films have attracted much attention due to their potential applications in memory devices. The aim of this paper is to review the main factors which can influence the ferroelectric domain structure in BiFeO₃ thin films, including substrate, doping and film thickness.

Abstract: We investigated domain structures in Pb(Zr,Ti)O₃ (PZT) ceramics whose composition lies on the morphotropic phase boundary (MPB) using transmission electron microscopy (TEM) and evaluated the piezoelectric properties of PZT. We found that monoclinic nanosized domains (nanodomains), which form in tetragonal domains, strongly correlated with the piezoelectric properties of PZT. The degree of formation of nanodomains depends on the grain composition. Thus, controlling the homogeneity of grain composition in the ceramics is crucial for optimizing the piezoelectric properties of PZT.

Abstract: A scanning nonlinear dielectric microscopy (SNDM) with an additional electrically conducting atomic force microscope cantilever as a probe needle is adopted to simultaneously observe the surface topographic and domain images of nanocrystalline BaTiO3 ceramics with super-high resolution. The sample exhibits a uniform grain size distribution and the average grain sizes are calculated to be about 30 nm. Some regions are brighter than the others in SNDM image, indicating the existence of ferroelectric domains structure. In addition, P-E hysteresis and piezoresponse loops are found in nanocrystalline BaTiO3 ceramics. The experimental results demonstrate that the SNDM with the function of atomic force microscopy is very useful for understanding domain structures of nanocrystalline ferroelectric materials.