Ferroelectric phase transition in relaxor ferroelectric single crystals 0.76PMN-0.24PT

来源 :科学通报(英文版) | 被引量 : 0次 | 上传用户:februaryliao
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
The features of the single crystals 0.76PMN-0.24PT in dielectric, ferroelectric, pyroelectric properties and domain structures indicate that they are located between typical ferroelectrics and normal ones. The unpoled crystals present a transitional domain configuration between microdomains and typical macrodomains while the crystals on (001) cuts undergo field-induced phase transition under poling, showing two special temperature points Td and Tm during the succedent heating procedure. The dielectric constant starts to decrease drastically at Td during cooling, or the transformation from induced macrodomain to transitional domain takes place at Td during heating. Ferroelectric-paraelectric phase transition or depolarization continues within the whole temperature range of Td-Tm, where ferroelectric phase in the form of transitional macrodomains coexists with paraelectric phase. Then the crystals macroscopically transoform into paraelectric phase containing ferroelectric microdomains at a temperature above Tm. However, owing to the influence of crystallite orientation on field-induced phase transition, the temperature Td does not appear in the same temperature-electric field history in multicrystal ceramics with the same composition as the above single crystals.
其他文献
陀螺两位置寻北中存在非线性航向误差,其测量航向角与真实的航向角差值的大小随真实航向角的变化而变化,呈现出近似为正(余)弦曲线的波动形式.本文分析了挠性陀螺寻北系统中
为了研究船用工程复合材料的界面裂纹特性,建立了刚性-压力敏感粘弹塑性材料Ⅰ型准静态扩展裂纹的力学模型.在稳态扩展阶段,应力和应变具有相同的奇异量级,即(σ,ε)∝γ
发动机机油压力的高低直接影响发动机的工作效率及发动机寿命,文章论述了容易造成发动机机油压力低的原因及解决的办法.
现今,聚酰胺(PA)纱作为复合地面系统的一部分,为驾驶提供了舒适的环境.但受成本的驱使,新的替代品不断涌现,如聚酯(PET)或聚丙烯(PP)纱线和针刺材料,以及聚乳酸纤维(PLA)和新
利用GRACE地球重力卫星的探测结果,反演了2004~2008年共60个月的全球地下水和地表水存储量的变化,采用滑动年平均的方法对全球地下水储量的时变特性进行了分析.揭示了全球地下
An inexpensive MC4044-based phase locked loop for constant speed control of a DC motor is discussed. It operates on a principle similar to that of a frequency s
This paper discusses the optimal nesting problem for minimizing the scrap in continuous shape stamping processes. The shape sliding technique is used to propose
甩负荷预测功能是确保机组甩负荷时汽轮机动态转速飞升不超标的一项重要措施.在试验(尤其是在大型汽轮机组)中发生该功能失效的情况并不多见.在分析具体试验数据的基础上,推
An optimization method to design turbine airfoils using a Genetic Algorithm (GA) design shell coupled directly with a viscous CFD (Computational Fluid Dynamics)
通过引入形状参数α,在双曲函数空间中构造了一类广义Bézier曲线,称其为HC-Bézier曲线.该曲线具有类似Bézier曲线的优良性质.当控制顶点固定时,通过调整形状参数α可以调