Ba_(0.85)Ca_(0.15)(Ti1−xZrx)O_(3)(BCTZ)ceramics with x=0.05,0.10,_(0.15),0.20,0.25,0.30 were prepared by the solid-state reaction method.Calcination of the powders was carried out at 1100°C for 4 h and the green ...Ba_(0.85)Ca_(0.15)(Ti1−xZrx)O_(3)(BCTZ)ceramics with x=0.05,0.10,_(0.15),0.20,0.25,0.30 were prepared by the solid-state reaction method.Calcination of the powders was carried out at 1100°C for 4 h and the green pellets were sintered at 1400°C for 2 h.X-ray diffraction patterns of the sintered pellets showed tetragonal splitting up to x=0.10 while the mixture of the rhombohedral/cubic phase appeared at higher ZrO_(2)concentrations.Maximum piezoelectric charge constant d33=510 pC/N and strain(S=0.103%)were measured for BCT doped by 0.10 mol ZrO_(2).Dielectric constant,remnant polarization and saturation polarization also found maxima for this composition.The Curie temperature(TC)of the compositions decreased with increase in ZrO_(2)concentration and reached 98°C,87°C and 36°C at x=0.05,0.10,_(0.15)mol,respectively.The remaining compositions have TC below the room temperature;therefore,they can be used for subzero/cryogenic applications.The scanning electron microscopy study revealed an increase in grain size with increase in ZrO_(2)concentration and confirmed the complete solubility of ZrO_(2)in the crystal lattice.Overall,low ZrO_(2)-doped BCT compositions with high d33 could be suitable for low temperature(<80°C)applications.展开更多
文摘Ba_(0.85)Ca_(0.15)(Ti1−xZrx)O_(3)(BCTZ)ceramics with x=0.05,0.10,_(0.15),0.20,0.25,0.30 were prepared by the solid-state reaction method.Calcination of the powders was carried out at 1100°C for 4 h and the green pellets were sintered at 1400°C for 2 h.X-ray diffraction patterns of the sintered pellets showed tetragonal splitting up to x=0.10 while the mixture of the rhombohedral/cubic phase appeared at higher ZrO_(2)concentrations.Maximum piezoelectric charge constant d33=510 pC/N and strain(S=0.103%)were measured for BCT doped by 0.10 mol ZrO_(2).Dielectric constant,remnant polarization and saturation polarization also found maxima for this composition.The Curie temperature(TC)of the compositions decreased with increase in ZrO_(2)concentration and reached 98°C,87°C and 36°C at x=0.05,0.10,_(0.15)mol,respectively.The remaining compositions have TC below the room temperature;therefore,they can be used for subzero/cryogenic applications.The scanning electron microscopy study revealed an increase in grain size with increase in ZrO_(2)concentration and confirmed the complete solubility of ZrO_(2)in the crystal lattice.Overall,low ZrO_(2)-doped BCT compositions with high d33 could be suitable for low temperature(<80°C)applications.
