Domain Structure Evolutions During the Poling Process for [011]-Oriented PMN-xPT Crystals Across the MPB Region

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• 作者：Chao Xu ; Qiang Li ; Qingfeng Yan ; Nengneng Luo ; Yiling Zhang and Xiangcheng Chu
• 刊名：Journal of the American Ceramic Society
• 出版年：2016
• 出版时间：June 2016
• 年：2016
• 卷：99
• 期：6
• 页码：2096-2102
• 全文大小：3509K
• ISSN：1551-2916

文摘

The poling effect on the [011]-oriented (1−x)Pb(Mg_1/3Nb_2/3)O₃-xPbTiO₃ (PMN–xPT) single crystals across the morphotropic phase boundary (MPB) was studied. The dielectric and piezoelectric properties were investigated as a function of the poling field. Domain structure evolutions during the poling process were recorded. In the unpoled PMN–xPT phase diagram, an apparent rhombohedral (R)-tetragonal (T) phase boundary exists. With room-temperature poling, the structure transformation sequence strongly depends on the composition. The crystal experiences a direct transition to the 2R/2T domain state in the rhombohedral or tetragonal phase field beyond the MPB region, whereas within the MPB zone it is hard to achieve the 2R/2T engineered configuration although the initial state is either rhombohedral or tetragonal as well. The piezoelectric responses of the MPB·PMN–xPTs are extraordinary weak (d₃₃ ~ 250 pC/N), in contrast to the [011]-oriented multidomain PMN–xPTs with ultrahigh-piezoelectric coefficient (d₃₃ > 1000 pC/N). We demonstrate that a slight composition variation near the MPB will significantly influence the domain evolution route and piezoelectricity for the [011]-oriented PMN–xPT crystals. We also confirm the feasibility to realize the 2R/2T engineered domain configuration for the [011]-oriented MPB crystals, which will extend the desired portion of the Bridgeman-grown boules with optimal piezoelectric properties.