Crystal growth and properties of novel multiferroic oxide compounds

新型多铁氧化物化合物的晶体生长和性能

• 批准号: 18263678
• 负责人: Dr. Dmitri Souptel
• 金额: --
• 依托单位: Leibniz-Institut für Festkörper- und Werkstoffforschung Dresden (IFW) e.V.
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2006
• 资助国家: 德国
• 起止时间: 2005-12-31 至 2007-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/18263678?language=en
• 关键词: Crystal; growth; properties; novel; multiferroic

There is an extremely increased interest to multiferroic materials such as RMn2O5 (R = rare earths) due to their promising applications as magnetoelectric materials those show strong coupling between magnetic and ferroelectric properties. The aim of this project is to grow and investigate single crystals of complex RMn2-xFexO5 and RMn2¿xCoxO5 oxides (R = Y, Tb, Ho) by two different crystal growth methods: by the conventional flux technique and the travelling solvent floating zone (TSFZ) technique. The reason of Fe and Co substitution of Mn in RMn2O5 is expected dramatic increase of temperatures (up to room temperatures), where strong magnetoelectric coupling and multiferroic behaviour appears, according to the recently obtained data on polycrystalline samples. In spite of the presence of the published results on investigation of undoped RMn2O5 crystals, no data were reported on the substituted single crystals. Therefore, the grown for the first time RMn2-xFexO5 and RMn2-xCoxO5 crystals will be studied with respect to their magnetic and ferroelectric properties, corresponding ordering temperatures and magnetoelectric effects depending on the nature of the doping element, its concentration level, valence states in the lattice and oxygen content. Crystal growth of the substituted compounds can help in understanding the fundamental problems in crystallization of doped RMn2O5 and the effects of doping element on variation of magnetoelectric properties for potential technological applications.

多铁性材料如RMn_2 O_5（R =稀土）由于其作为磁电材料的应用前景而引起了人们极大的兴趣，这些材料表现出磁性和铁电性之间的强耦合。本项目的目的是通过两种不同的晶体生长方法生长和研究复杂RMn 2-xFexO 5和RMn 2 <$xCoxO5（R = Y，Tb，Ho）的单晶：通过常规助熔剂技术和移动溶剂浮区技术（TSFZ）。根据最近获得的多晶样品的数据，在RMn_2 O_5中Fe和Co取代Mn的原因是预期温度的急剧升高（高达室温），其中出现强磁电耦合和多铁性行为。尽管存在对未掺杂的RMn 2 O 5晶体的研究的公布结果，但没有关于取代的单晶的数据报道。因此，第一次生长的RMn 2-xFexO 5和RMn 2-xCoxO 5晶体将研究其磁性和铁电性能，相应的有序温度和磁电效应取决于掺杂元素的性质，其浓度水平，晶格中的价态和氧含量。取代化合物的晶体生长有助于理解掺杂RMn_2 O_5晶化的基本问题以及掺杂元素对磁电性能变化的影响，从而为潜在的技术应用提供参考。