Sintering temperature and iso-valent dopant effects on microstructural and dielectric properties of lead-free ceramic La0.01(Ba1-xCax)0.99Ti0.9975O3

Ca-doped Lanthanum barium titanate La0.01Ba0.99Ti0.9975O3 ceramics powders were prepared by sol-gel process . Sintering of pressed powders was performed at 1150°C, 1250°C and 1300°C for 4 hours.Microstructure morphology was analyzed using Scanning Electron Microscopy (SEM), and the grain size of the samples was estimated. Dielectric measurements were carried out with an impedance-analyzer in the temperature range from room temperature (RT) to 250°C, and for frequencies ranging from 100Hz to 1MHz

ORIENTAL JOURNAL OF CHEMISTRY Physicochemical Characteristic of BaTi 0.95 Zr 0.05 O 3

ABSTRACT Physical and chemical properties of BaTiO 3 (BT) and BaTi 0.95 Zr 0.05 O 3 (BZT0.05) ceramics have been studied. These powders are prepared by the Sol-gel process and calcined at different temperatures [500°C-1000°C]. X-Ray Diffraction (XRD) showed a crystallization of BT and BZT0.05 powders in the perovskite phase after a calcination temperature at 600°C, during 4 hours, but in the presence of some traces of zirconium oxide for the doped powder. Also, the effect of zirconium addition on dielectric properties to BT is analyzed. Indeed, dielectric measurements carried out have shown the presence of a second anomaly for Zr doped material at 60°C; an anomaly that has been attributed to structural transition

Structural, electric and dielectric properties of Eu-doped SrBi2Nb2O9 ceramics obtained by co-precipitation route

This paper presents a study of the structure and dielectric properties of Eu-doped SrBi2Nb2O9 ceramics prepared by co-precipitation route and sintered at 850 °C. The materials were examined using XRD and FTIR methods. XRD data indicated the formation of well crystallized structure of the pure and doped SrBi2Nb2O9, without the presence of undesirable phases. FTIR spectra do not bring a significant shift in the band positions. Moreover, the AC conductivity, dielectric constant and dielectric loss of the ceramics were determined through the frequency range [50 kHz–1 MHz]. In particular, the dielectric constant (ε′) and dielectric losses (tan δ) of the SrBi2Nb2O9 and SrBi1.6Eu0.4Nb2O9 ceramics were measured as a function of temperature at various frequencies