RFeO3型正铁氧体中多铁性与自旋重取向特性的中子散射研究

项目名称： RFeO3型正铁氧体中多铁性与自旋重取向特性的中子散射研究

项目编号： No.11505296

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 刘新智

作者单位： 中国原子能科学研究院

项目金额： 23万元

中文摘要： RFeO3型正铁氧体由于新近发现的多铁性和丰富的自旋重取向行为受到广泛重视。在R稀土离子磁有序温度以下已发现具有由于交换伸缩机制导致的多铁性，而室温多铁性的存在性还存在争议。另一方面自旋重取向特性也是本体系一个重要特征，可能为我们提供更多的有趣的多铁材料。本课题拟采用中子散射为主要手段，通过粉末衍射获取其精确磁结构和自旋重取向行为，通过非弹性中子散射获取其自旋波色散关系。对其精确磁结构进行对称性分析，通过波色散关系提取其Fe-Fe和Fe-R作用强度，揭示其多铁性、自旋重取向特性与磁性相互作用的内在机制。

中文关键词： RFeO3型正铁氧体；多铁性；自旋重取向；中子衍射；中子非弹性散射

英文摘要： Recently, RFeO3 type orthoferrite has attracted lots of attentions due to the multiferroic property and rich spin reorientation behaviors. It has been found the magnetic field induced ferroelectricity below the R3+ ions order temperature caused by the exchange-striction mechanism. However, the existence of multiferroicity at the RT is still controversial. On the other hand, the spin reorientation is also an important character for understanding the magnetic interaction of this system. It also provides us more magnetic structures as candidates of new multiferroic materials. To get a deeper insight of the relation between multiferroic, spin reorientation and magnetic interaction in this system, we plan to perform the investigation on the magnetic structure and spin dynamic using neutron scattering. The symmetric analysis based on the accurate magnetic structure from the powder diffraction will provide the evidence of multiferroicity, while the evolution of Fe-Fe and Fe-R exchange interaction extracted from the spin wave dispersion will demonstrate the origin of spin reorientation.

英文关键词： RFeO3 orthoferrite;multiferroicity;spin reorientation;neutron powder diffraction;inelastic neutron scattering