Structural, thermal, dielectric and ferroelectric properties of Na0.5K0.5NbO3and Na0.5K0.5NbO3+0.5mol%MnO2ceramics
Lead-free Na0.5K0.5NbO3 and Na0.5K0.5NbO3+0.5mol%MnO2 ceramics were fabricated by solid state hot pressing sintering process. The phase structure and thermal, dielectric and ferroelectric properties of these ceramics were investigated. X-ray measurements showed that all samples have a single perovskite structure and possess orthorhombic–tetragonal and tetragonal–cubic phase transitions. Sequence of phase transitions was confirmed by differential scanning calorimetry (DSC) and dielectric measurements. Obtained results showed that optimal temperature sintering of Na0.5K0.5 NbO3+0.5mol%MnO2 ceramics is 1100 °C. The results show that investigated ceramics are one of the promising materials as e…
Influence of Sr addition on structural, dielectric and Raman properties of Na0.5Bi0.5TiO3ceramics
ABSTRACTLead free (Na0.5Bi0.5)1-xSrxTiO3 (x = 0, 0.01 and 0.02) ceramics were produced by a conventional solid-state sintering method. X-ray diffraction analysis shows that the obtained samples possess the perovskite structure with rhombohedral symmetry. The microstructure study shows a dense structure, in agreement with the relative density (above 97%). Dielectric analysis revealed the diffuse character of the electric permittivity anomalies and their shift to a lower temperature range after Sr doping of NBT. The Raman spectra are similar for all samples in agreement with the X-ray diffraction data. The possible origin of the observed effects was discussed.