Papers by Keyword: Nanocrystalline BaTiO₃ Ceramics

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.

Abstract: The full potential linearized augmented plane wave method within the generalized gradient approximation was used to calculate electronic structure of nanocrystalline BaTiO3 ceramics. We calculated the total and partial density of states of 50 nm BaTiO3 ceramics. The results show that the atoms distribution of nanograin BaTiO3 ceramics is different from those of coarse BaTiO3 ceramics. It is also revealed that the hybridization between Ti 3d and O 2p is very strong, which is very important to the ferroelectric stability of nanocrystalline BaTiO3 ceramics.