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Item type:Publication, Low firing temperatures and high ferroelectric properties of (Ba0.85Ca0.15)(Ti 0.90Zr0.10)O3 lead-free ceramics synthesized by the combustion technique(2016-01-26); Bongkarn, TheerachaiThis work studied the effect of firing conditions on phase formation, microstructure and electrical properties of (Ba<inf>0.85</inf>Ca<inf>0.15</inf>)(Ti<inf>0.90</inf>Zr<inf>0.10</inf>)O<inf>3</inf>;(abbreviated as BCTZ) ceramics, which were synthesized through the combustion technique. To reduce the reaction temperature, glycine was used as fuel with a ratio of raw material: glycine (1:1.11). BCTZ samples were calcined at 900-1200°C for 2 h and sintered at 1350 -1550°C for 2 h. Ultrafine BCTZ powder and single peroveskite phase were achieved from the sample calcined at 1050°C for 2 h.These results were obtained at a lower temperature and with shorter dwell time than those obtained using the solid state reaction method by ∼150°C and 1 h, respectively. The BCTZ ceramics exhibited a coexistence of rhombohedral and orthorhombic phase in all samples. The average particle size and the average grain size increased from 172 to 295 nm and 0.82 to 2.57 μm, respectively, when firing temperatures increased. The highest density (5.76 g/cm<sup>3</sup>), highest dielectric constant (ε<inf>r</inf> ≅ 4485 and ε<inf>max</inf> ≅ 14897) and best ferroelectric properties (P<inf>r</inf> ≅ 18.47 C/cm<sup>2</sup> and E<inf>C</inf> ≅ 4.52 kV/cm) were obtained from the sample sintered at 1450°C for 2 h.1 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Fabrication of new (Ba0.97Ca0.03)(Zr0.94Sn0.06)O3 ceramics by the combustion technique(2016-01-26); Bongkarn, TheerachaiIn this study, new (Ba<inf>0.97</inf>Ca<inf>0.03</inf>)(Zr<inf>0.94</inf>Sn<inf>0.06</inf>)O<inf>3</inf> BCZS ceramics were synthesized by the combustion technique using glycine as fuel. The powders and ceramics were calcined from 1,000 to 1,200 °C for 2 h and sintered from 1,500 to 1,675 °C for 2 h. A pure perovskite phase was found in the powder calcined at higher than 1,150 °C and the purity phase of the ceramics was detected in all samples. The average particle size and grain size increased approximately from 73 to 103 nm and from 0.51-1.61μm when firing temperatures increased. The calcined powders exhibited tight agglomerates at low calcination temperatures and they changed to loosely bound agglomerates at higher calcination temperatures. The densest ceramics were discovered in the samples sintered at 1,650 °C. The dielectric constant (ε<inf>r</inf>) and loss factor (tan δ) values measured at 100 kHz of this sample were found to be 44 and 0.01, respectively at room temperature.1