Nanoscale clusters and phonon anomalies in relaxor-ferroelectric

弛豫铁电体中的纳米级团簇和声子异常

• 批准号: 15111464
• 负责人: Professorin Dr. Boriana Mihailova
• 金额: --
• 依托单位: Mineralogisch-Petrographisches Institut (MPI)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2005
• 资助国家: 德国
• 起止时间: 2004-12-31 至 2008-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/15111464?language=en
• 关键词: Nanoscale; clusters; phonon; anomalies; relaxor

Relaxor ferroelectrics are key multi-functional materials because of their high dielectric permittivity, piezoelectric and optoelectic coefficients, which are basis of a number of technological applications including RAMs. They exhibit diffuse phase transitions over a broad temperature range, frequency dependence of the dielectric-permittivity maximum and subtle structural anisotropy to long-coherence probe radiation. The interplay between local chemical variations, polar-cluster formation and dynamics, and the unique relaxor properties is still far from being well understood. Polarised Raman spectroscopy, synchrotron X-ray diffraction as well as piezoresponse force microscopy (PFM) will be applied to doped lead-based perovskite-type single-crystal relaxors, in order to analyse the chemically-induced changes in the ferroic clusters. Our research will focus mainly on La-doped PbSc0.5B”0.5O3 (B” = Ta, Nb) as well as on PbZn1/3Nb2/3O3-PbTiO3. PFM analyses will be conducted also on Ba- and Ru- doped relaxor-ferroelectrics investigated during the previous project MI 1127/1-1. The results achieved within this project will give further insights into the atomic clustering responsible for the relaxor properties and will be of high significance for the design of innovative technologically important materials.

弛豫铁电体因其高介电常数、压电系数和光电系数而成为关键的多功能材料，这是包括RAM在内的许多技术应用的基础。它们在很宽的温度范围内表现出弥散相变，介电常数最大值的频率依赖性，以及对长相干探测辐射的微妙的结构各向异性。局部化学变化、极性团簇的形成和动力学以及独特的弛豫特性之间的相互作用仍然远未被很好地理解。偏振拉曼光谱、同步辐射X射线衍射以及压电响应力显微镜(PFM)将被用于掺杂铅基钙钛矿型单晶弛豫材料，以分析化学诱导的铁性团簇的变化。我们的研究将主要集中在La掺杂PbSc0.5B“0.5O_3(B”=Ta，Nb)以及PbZn_1/3Nb_2/3O_3-PbTiO_3。PFM分析还将对在前一个项目MI 1127/1-1期间调查的掺Ba和Ru的弛豫铁电体进行。该项目所取得的成果将使人们进一步深入了解导致弛豫特性的原子团簇，并将对创新的重要技术材料的设计具有重要意义。

项目成果

Structural, optical and dielectric properties of relaxor-ferroelectric Pb0.78Ba0.22Sc0.5Ta0.5O3

弛豫铁电体 Pb0 78Ba0 22Sc0 5Ta0 5O3 的结构、光学和介电特性

• DOI: 10.1088/0953-8984/18/31/l01
• 发表时间: 2006
• 期刊: Journal of Physics: Condensed Matter
• 作者: Marinova;Mihailova;Malcherek;Paulmann;Lengyel;Kovacs;Veleva;Gospodinov;Güttler;Stosch;Bismayer
• 通讯作者: Bismayer