A Modified Iterative Automatic Method for Characterization at Shear Resonance: Case Study of BaCaTiZrO Eco-Piezoceramics.

Coupling between electrically excited electromechanical resonances of piezoelectric ceramics is undesirable for the purpose of their characterization, since the material models correspond to monomodal resonances. However, coupling takes place quite often and it is unavoidable at the shear resonance of standard in-plane poled and thickness-excited rectangular plates. The piezoelectric coefficient , the elastic compliance and the dielectric permittivity component for a piezoelectric ceramic can be determined, including all losses, using the automatic iterative method of analysis of the complex impedance curves for the shear mode of an appropriated resonator.

Luminescence properties of Yb-doped SrTiO: the significance of the oxygen-titanium charge transfer state on photon downshifting.

Ceramic powders of Sr1-1.5xYbxTiO3 (x = 0.0, 0.

Optical and Piezoelectric Study of KNN Solid Solutions Co-Doped with La-Mn and Eu-Fe.

The solid-state method was used to synthesize single phase potassium-sodium niobate (KNN) co-doped with the La-Mn and Eu-Fe ion pairs. Structural determination of all studied solid solutions was accomplished by XRD and Rietveld refinement method. Electron paramagnetic resonance (EPR) studies were performed to determine the oxidation state of paramagnetic centers.

Piezoelectric Ceramics of the (1 - x)BiNaTiO₃-xBaCaTiO₃ Lead-Free Solid Solution: Chemical Shift of the Morphotropic Phase Boundary, a Case Study for x = 0.06.

Research and development of lead-free piezoelectric materials are still the hottest topics in the field of piezoelectricity. One of the most promising lead-free family of compounds to replace lead zirconate-titanate for actuators is that of BiNaTiO₃ (BNT) based solid solutions. The pseudo-binary (1 - )BiNaTiO₃-BaCaTiO₃ system has been proposed for high temperature capacitors and not yet fully explored as piezoelectric material.

Development of AlN and TiB₂ Composites with Nb₂O₅, Y₂O₃ and ZrO₂ as Sintering Aids.

The synthesis of AlN and TiB₂ by spark plasma sintering (SPS) and the effect of Nb₂O₅, Y₂O₃ and ZrO₂ additions on the mechanical properties and densification of the produced composites is reported and discussed. After the SPS process, dense AlN and TiB₂ composites with Nb₂O₅, Y₂O₃ and ZrO₂ were successfully prepared. X-ray diffraction analysis showed that in the AlN composites, the addition of Nb₂O₅ gives rise to Nb₄N₃ during sintering.