新型类钙钛矿Mn2BB՛O6多铁性材料的探索与磁电耦合效应研究

Multiferroic and magnetoelectric effect has potential applications in novel electronic devices. However, most of the muiltiferroics reported to date have relatively low magnetoelectric coupling temperatures. It is very important to explore the novel high-temperature multiferroics for the practical application. In this project, the double perovskite like oxide Mn2BB՛O6 with Mn ions in the A site will be prepared by high temperature and high pressure method. The B/B՛ ion species, B/B՛ ion՛s degree of order, the sample preparation and annealing process, and other factors that affect the sample crystal structure and magnetic structure will thoroughly study. The purpose is to explore and design the new Mn2BB՛O6 multiferroics. In addition, the physical mechanism of the magnetoelectric coupling of the novel multiferroics will be studied by macroscopic physical measurements such as magnetic, electrical transport, dielectric and magnetoelectric coupling effects, combined with advanced experimental methods such as neutron diffraction.

多铁性与磁电耦合效应在新型电子器件方面有潜在应用前景。但已报导的大部分磁致铁电极化多铁性材料的磁电耦合温度都较低，探索开发新型高温多铁性材料对于推动此类材料的实用化至关重要。本项目采用高温高压方法制备A位为Mn离子的类钙钛矿氧化物Mn2BB՛O6。系统阐述B/B՛位离子种类、有序度，样品的制备工艺及后期热处理工艺等因素对样品晶体结构和磁结构的影响，探索与设计新型Mn2BB՛O6磁致铁电极化多铁性材料。通过磁性、电输运、介电、磁电耦合效应等宏观物性测量，结合中子衍射等先进实验方法，阐明新型磁致多铁性材料磁电耦合的微观物理机制。

多铁性与磁电耦合效应在新型电子器件方面有潜在应用前景。新型磁电多铁性材料开发对于推动此类材料的实用化至关重要。异常钙钛矿因A、B位都可以由小半径过渡金属元素占据，会产生更加复杂的结构畸变和磁性交互作用，是极具潜力的新型磁电多铁性材料。然而，异常钙钛矿材料多为亚稳态，需借助高温高压法合成。本项目通过化学压力辅助，在较温和条件下制备了系列异常钙钛矿；采用大数据驱动高通量计算，预测并精准制备了新型异常钙钛矿极性磁体。通过电输运、磁性、磁介电、磁电耦合等宏观物性测量，结合同步辐射，中子衍射等先进实验方法，研究了新型异常钙钛矿结构相变与电、磁学性能的关系，阐明磁电耦合的微观机制。该项目也拓展研究了六角铁氧体的磁、电及磁电耦合性能，为高温磁电多铁性材料开发做出了一定的研究成果。在本项目资助下所获得的相关研究成果已在国际知名学术期刊npj Quantum Mater.，J. Mater. Chem. C，Chem. Mater.，Inorg. Chem.等发表SCI论文9篇。