Dislocation-density changes upon poling of polycrystalline BaTiO3
نویسندگان
چکیده
We report evidence for a significant increase of bulk dislocation density upon poling of polycrystalline BaTiO3. The synchrotron high-resolution x-ray-diffraction measurements yield a dislocation density on the order of 10/cm and an associated strain-energy increase of about 20 kJ/m. This implies that the application of an external poling field generates defects in the structure and increases the internal stress. Possible consequences in both bulk and thin-film applications include accelerated aging and microcracking. @S0163-1829~99!06005-1#
منابع مشابه
Unique single-domain state in a polycrystalline ferroelectric ceramic
Non-180° ferroelectric domains are also ferroelastic domains; their existence in polycrystalline materials is to relieve internal stresses generated during solid-solid phase transitions and minimize the elastic distortion energy. Therefore, grains with random orientations in polycrystalline ceramics are always occupied by many domains, especially in the regions close to grain boundaries. In thi...
متن کاملA New Phase Boundary in (Bi1/2Na1/ 2)TiO3BaTiO3 Revealed via a Novel Method of Electron Diffraction Analysis
A new phase boundary is revealed in (1-x)(Bi1/2Na1/2)TiO3xBaTiO3, the most extensively studied leadfree piezoelectric solid solution. This discovery results from a novel method of electron diffraction analysis, which allows for the precise determination of oxygen octahedra tilting in multi-domain perovskite ferroelectrics. The study using this method supports the recently proposed Cc symmetry ...
متن کاملبررسی توزیع انرژی ذخیره شده تغییر شکل در داخل پلیکریستال فلزی با استفاده از تئوری کریستال پلاستیسیته بر مبنای چگالی نابجایی
The stored deformation energy in the dislocation structures in a polycrystalline metal can provide a sufficient driving force to move grain boundaries during annealing. In this paper, a thermodynamically-consistent three-dimensional, finite-strain and dislocation density-based crystal viscoplasticity constitutive theory has been developed to describe the distribution of stored energy and dislo...
متن کاملEvolving morphotropic phase boundary in lead-free (Bi1/2Na1/2)TiO3–BaTiO3 piezoceramics
The correlation between structure and electrical properties of lead-free (1−x)(Bi1/2Na1/2)TiO3–xBaTiO3 (BNT-100xBT) polycrystalline piezoceramics was investigated systematically by in situ synchrotron diffraction technique, combined with electrical property characterization. It was found that the morphotropic phase boundary (MPB) between a rhombohedral and a tetragonal phase evolved into a morp...
متن کاملCreation and destruction of morphotropic phase boundaries through electrical poling: a case study of lead-free (Bi(1/2)Na(1/2))TiO3-BaTiO3 piezoelectrics.
We report the first direct evidence that the morphotropic phase boundary in ferroelectric materials, along with the associated strong piezoelectricity, can be created, destroyed, or even replaced by another morphotropic phase boundary through phase transitions during electrical poling. The real-time evolution of crystal structure and domain morphology during the poling-induced phase transitions...
متن کامل