钇元素掺杂对BCT-BZT无铅陶瓷的结构与压电性能影响

发布时间：2018-06-15 14:47

本文选题：功能材料 + 无铅压电陶瓷　；参考：《哈尔滨理工大学》2017年硕士论文

【摘要】：铁电压电材料因其具有良好的压电性、铁电性和热释电性等特性成为了重要的功能材料之一,在存储器,传感器,通讯设备和换能器中都有重要的应用。目前铁电压电性能最优异,应用最广泛的陶瓷材料是锆钛酸铅系陶瓷材料,但因其原材料中含有铅元素,在生产和废弃处理时会对环境造成污染,所以研发出性能优异能够替代铅基材料的无铅压电陶瓷成为了研究的重点。赝二元体系的[x(Ba0.7Ca0.3)Ti O3-(1-x)Ba(Zr0.2Ti0.8)O3](简称x BCT-(1-x)BZT)无铅压电陶瓷性能优越,且通过组分设计可以调节准同型相界区域,引起了广大研究学者的关注,成为了替代铅基陶瓷材料的选择之一。掺杂改性是比较常见的提高陶瓷材料性能的一种方法,通过引入适量的掺杂物,可以对陶瓷的某些性能进行改进。本论文选用氧化钇作为掺杂剂,研究了钇元素引入对50BCT-50BZT陶瓷材料性能的影响。论文用传统固相反应法制备了50BCT-50BZT无铅陶瓷,摸索了陶瓷的烧结特性。通过物相分析发现样品呈现典型的ABO3钙钛矿结构,无杂相生成,钇元素成功的固溶进50BCT-50BZT陶瓷的晶格中,形成了均一稳定的固溶体。扫描电镜图观察到钇元素的引入使陶瓷的气孔减少,致密度增加。对样品不同频率下,不同温度下的相对介电常数和损耗等介电性能的进行了测试,发现钇元素的引入可以提高陶瓷样品的介电性能。频率为100 Hz时,掺杂含量为0.6 mol%的陶瓷样品的室温相对介电常数最大,约为2175;随着钇元素掺杂含量的增加,陶瓷样品的损耗略有增大。论文对样品进行了铁电压电性能测试,探究了钇元素引入对50BCT-50BZT陶瓷的铁电压电性能的影响规律。随着掺杂含量的增加,样品的极化强度展现出先增加后减小的趋势;掺杂含量为0.4 mol%时,样品具有最大的剩余极化强度Pr=6.38μC/cm2。由陶瓷样品的应变/电压的蝶形曲线,计算得到逆压电系数d33*;随着钇元素掺杂含量的增加,样品的逆压电系数先增大后减小,掺杂含量为0.2 mol%时样品具有最大的逆压电系数d*33=494 pm/V。
[Abstract]:Ferroelectric materials have become one of the important functional materials because of their good piezoelectric properties, ferroelectric properties and pyroelectric properties. They have important applications in memory, sensors, communication equipment and transducers. At present, the most excellent ferroelectric properties and the most widely used ceramic materials are lead zirconate titanate materials. However, due to the lead element in its raw materials, it will pollute the environment in production and waste treatment. Therefore, the research of lead-free piezoelectric ceramics which can replace lead-based materials with excellent performance has become the focus of research. In pseudo-binary system, [xBCT-N1-xBZT] (x BCT-T 1-x BZT) lead-free piezoelectric ceramics have excellent properties, and the quasi-homogeneous phase boundary region can be adjusted by component design, which has attracted the attention of many researchers and has become one of the choices for substituting lead-based ceramic materials for the study of the pseudo-binary system [xBC-0.7Ca _ (0.3) Mo _ (3) O _ (1-x) Ba _ (2) Zr _ (0.2) Ti _ (0.8) O _ (3). Doping modification is a common method to improve the properties of ceramic materials. Some properties of ceramics can be improved by introducing appropriate amount of dopants. In this paper, yttrium oxide was used as dopant to study the effect of yttrium on the properties of 50BT-50BZT ceramics. In this paper, 50BCT-50BZT lead-free ceramics were prepared by the traditional solid state reaction method, and the sintering characteristics of the ceramics were explored. By phase analysis, it was found that the sample had typical ABO3 perovskite structure, no impurity phase formation, and the yttrium element was successfully dissolved into the lattice of 50BCT-50BZT ceramics, forming a homogeneous and stable solid solution. Scanning electron microscopy showed that the introduction of yttrium elements reduced the porosity and increased the density of ceramics. The dielectric properties such as relative dielectric constant and loss were measured at different frequencies and temperatures. It was found that the introduction of yttrium elements could improve the dielectric properties of ceramic samples. When the frequency is 100 Hz, the relative dielectric constant of the ceramic sample doped with 0.6 mol% is the largest at room temperature, about 2175, and with the increase of the doping content of yttrium, the loss of ceramic sample increases slightly. In this paper, the ferroelectric properties of 50BCT-50BZT ceramics were tested, and the influence of the addition of yttrium on the ferroelectric properties of 50BCT-50BZT ceramics was investigated. With the increase of doping content, the polarization strength of the samples increased first and then decreased, and the maximum residual polarization strength Pr6.38 渭 C / cm ~ 2 was obtained when the doping content was 0.4 mol%. Based on the butterfly curve of strain / voltage of ceramic sample, the inverse piezoelectric coefficient d33494 pm / v was calculated with the increase of doping content of yttrium element, the inverse piezoelectric coefficient of the sample increased first and then decreased. When the doping content was 0.2 mol%, the sample had the largest inverse piezoelectric coefficient dn33494 pm / v.
【学位授予单位】：哈尔滨理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ174.1

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