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Beyond the possibility of finding a lead-free piezoceramics as replacement for PZT, the world-wide research has focused on other mechanisms of electro-mechanical coupling alternative to piezoelectricity, such as electrostriction and, more recently, flexoel ...
The manner in which 90. ferroelectric-ferroelastic domains respond to changes in temperature has been mapped in BaTiO3 single crystals using atomic force microscopy. Domain periodicity remains unaltered until approximately 2 degrees C below the Curie tempe ...
A centrosymmetric stress cannot induce a polar response in centric materials; piezoelectricity is, for example, possible only in non-centrosymmetric structures. An exception is meta-materials with shape asymmetry, which may be polarized by stress even when ...
Despite the technological importance of hard and soft PZT, Pb(Zr,Ti)O3, ceramics, the mechanisms of ferroelectric hardening and softening remain widely discussed in the literature. The hardening and softening phenomena have traditionally been investigated ...
Strain response of polycrystalline barium titanate (BaTiO3) was investigated under high unipolar electric field (0 to 4 kV/mm) and compressive stress (0 to 400 MPa) in the temperature range from 25 to 160 degrees C. In the vicinity of the Curie point (T-C) ...
We report on the frequency and stress dependence of the direct piezoelectric d33 coefficient in BiFeO3 ceramics. The measurements reveal considerable piezoelectric nonlinearity, i.e., dependence of d33 on the amplitude of the dynamic stress. The nonlinear ...
This thesis consists of a theoretical analysis of charged domain walls in ferroelectrics based on Landau theory and the theory of semiconductors. First, the internal structure of a 180-degree charged domain wall is considered. It is shown that different re ...
Ferroelectric orthorhombic lead metaniobate (PbNb2O6) is known to be metastable with respect to the thermodynamically stable nonferroelectric rhombohedral polymorph. The high-temperature tetragonal to low temperature rhombohedral phase transition is recons ...
This work was originally motivated by the search for high-temperature piezoceramic materials with low acoustic impedance and high electromechanical coupling. The temperature and pressure behavior of two PZT-based materials with engineered porosity, Pz31 & ...
Orthorhombic Lead metaniobate (PbNb2O6) exhibits ferroelectric properties and has a Curie temperature, TC of 570 degrees C. This work reports on investigations made on ferroelectric Lead metaniobate, (PN) and its solid solutions with bismuth and titanium P ...
