A. Niewiadomski

University of Silesia in Katowice · Institute of Physics

High quality lead-free Na0.5Bi0.5TiO3 (NBT) single crystals were grown by the Czochralski method. The XRD patterns indicate the perovskite-type structure of rhombohedral symmetry with small amount of tetragonal phase even at room temperature. Structural, Raman scattering, thermal, dielectric and second harmonic generation (SHG) studies were perform...

Dense K0.5Bi0.5TiO3 (KBT) lead-free ceramics were prepared by conventional solid reaction route. Their temperature behavior (up to 600°C) was investigated by X-ray diffraction, DSC, dielectric spectroscopy and electric field-polarization technique. The first temperature dependent Raman scattering studies were also performed. X-ray and Raman scatter...

Silver–lithium niobate, Ag 1 À x Li x NbO 3 , is a promising candidate for lead-free piezoelectrics. Ceramic samples for x equal 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.08 and 0.1 were synthesized by solid state reaction. Room temperature X-ray studies indicate that all samples consist mainly of perovskite phase. Only small amounts of secondary phase...

Good quality Bi2WO6 (BWO) single crystals were grown by the flux method. Transparent, light red, plate-like with sharp triangular shape BWO-A crystals were grown using NaVO3-B2O3 solvent. Transparent, light green, plate-like BWO-B crystals were obtained using Na2WO4 solvent. X-ray diffraction and scanning electron microscopy studies showed that bot...

Silver lithium niobates Ag1−xLixNbO3 are promising lead free piezoelectrics. Good quality Ag0.96Li0.04NbO3 ceramics were obtained. Dielectric and DSC studies showed that, in comparison to AgNbO3, temperatures of phase transitions slightly decrease. Dielectric studies pointed to enhancement of polar properties. Remnant polarisations achieves value o...

0.82K0.5Bi0.5TiO3-0.18PbTiO3 ceramic was fabricated by the mixed oxide method. An X-ray study shows that the obtained ceramic has a pure perovskite structure. The ϵ(T) and tanδ(T) show a peak centered at about 468 °C and 421 °C, respectively, and related to the tetragonal-cubic phase transition. The effect of uniaxial pressure (0-1500 bar) on diele...

Silver niobate AgNbO3 is a promising basic compound for high permittivity microwave dielectrics and lead-free piezoelectrics. Stoichiometric and nonstoichiometric AgxNbO2.5+x/2 ceramics were obtained for x equal to 0.95, 0.98, 1.00, 1.02, and 1.05. Scanning electron microscopy and X-ray diffraction studies showed that the homogeneity of the perovsk...

Bi2WO6 single crystals were grown by a flux method using two solvents: NaVO3B2O3 and NaWO4. Dielectric studies were performed in the temperature range from 110 to 940?K. They showed that dielectric permittivity along the ferroelectric axis shows slight dispersion, increases with increasing temperature and reaches local maximum related to the P21 ab...