Hernández-Moreno Ana Cristina, Reyes-Montero Armando, Carreño-Jiménez Brenda, Acuautla Mónica, Pardo Lorena
Facultad de Química, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Cd. Universitaria, Coyoacán C.P. 04510, CDMX, Mexico.
Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Cd. Universitaria, Coyoacán C.P. 04510, CDMX, Mexico.
Materials (Basel). 2023 Mar 11;16(6):2268. doi: 10.3390/ma16062268.
BaCaTiZrO (BCZT8-5) ceramic materials have been scarcely studied as lead-free piezo/ferroelectrics despite their enhanced Curie temperature (>100 °C) with respect to most studied BCZT compositions. In this work, homogeneous dense BCZT8-5 ceramics with grain size in the range of 20 μm, and optimum ferroelectric, dielectric, and electromechanical performance, were prepared by the mixed oxides route using moderate synthesis (1250 °C-2 h) and sintering (1400 °C-2 h) conditions. Thickness-poled thin disks and monomodal shear plate resonators were used for the determination of piezoelectric coefficients, coupling factors, elastic, and dielectric permittivity coefficients, including all losses, by iterative analysis of impedance curves at resonance. Furthermore, the thermal evolution of the piezoelectric characteristics at resonance was determined to assess the enhanced working range of the ceramics (≈100 °C). Ferroelectric hysteresis loops and strains vs. electric-field butterfly loops were also measured and showed soft behavior with E = 2 kV/cm, P = 12 μC/cm after a maximum applied field of 3 kV was used. The ceramics showed a high endurance of P-E cycles to electrical fatigue up to 10 cycles. Moreover, dielectric properties as a function of temperature were also accomplished and showed nearly normal ferroelectric behavior, characteristic of samples with low crystallographic disorder. Overall, these ceramics showed high sensitivity and higher stability than other currently studied BCZT compositions.
尽管BaCaTiZrO（BCZT8-5）陶瓷材料相对于大多数已研究的BCZT成分具有更高的居里温度（>100°C），但作为无铅压电/铁电材料却鲜有研究。在这项工作中，通过混合氧化物法，采用适度的合成条件（1250°C - 2小时）和烧结条件（1400°C - 2小时），制备出了晶粒尺寸在20μm范围内、具有最佳铁电、介电和机电性能的均匀致密BCZT8-5陶瓷。通过对共振时阻抗曲线的迭代分析，使用厚度极化的薄圆盘和单峰剪切板谐振器来测定压电系数、耦合因子、弹性和介电常数系数，包括所有损耗。此外，还测定了共振时压电特性的热演化，以评估陶瓷的增强工作范围（≈100°C）。还测量了铁电滞回环以及应变与电场的蝴蝶环，在施加最大电场3 kV后，显示出在电场强度E = 2 kV/cm、极化强度P = 12 μC/cm时的软特性。这些陶瓷在高达10次循环的电疲劳下表现出对P-E循环的高耐久性。此外，还完成了介电性能随温度的变化，显示出近乎正常的铁电行为，这是低晶体无序样品的特征。总体而言，这些陶瓷比目前研究的其他BCZT成分表现出更高的灵敏度和稳定性。
