电子相分离界面耦合调控受限空间核壳团簇的磁电输运

There are lots of advantages in property regulation for core-shell clusters which include fruitful magnetic and electronic properties. Exhaustive researches have executed for the microstructure and magnetic property. But the study of electronic, magnetic transport regulation and mechanisms are developed slowly due to the limitation of experimental conditions and influence of surface, interface effect. The development and application of small scale cluster based magnetic, electric memories are the aim which cluster science and nanotechnology are currently working on. This project intends to regulate the magnetic, electronic transport of core-shell cluster assembled devices. By utilizing the character of strong interfacial coupling for clusters in confined space and the multi-filed modulated electronic phase separation in LaxSr1-xMnO3, PrxCa1-xMnO3 strongly correlated systems offered different interfaces including metallic (ferromagnetic)-insulating (antiferromagnetic) co-existed various ordered phases to achieve this intention. Firstly, we explore the rule of property regulation and magnetic phase transition from interfacial coupling interaction in different composition, magnetic structure of parent clusters, core-shell thickness, and scale of confined space. Then, mechanisms of interfacial coupling regulated cluster spin order and electronic structure will be revealed based on magnetic domain switching dynamics. Further, the law and mechanism will guide the design of cluster devices and new materials. This project opens a new route for the design and performance regulation of cluster assembled devices at mesoscale.

核壳团簇的强界面耦合和多界面特点在性能调控方面有许多优越性，包含丰富的磁电性能。其微结构和磁性被广泛的研究。但受实验条件和团簇自身表面、界面效应的影响，对小尺度团簇器件磁电输运性能的调控和机理研究进展缓慢。而团簇磁电存储器件的应用开发一直是团簇学和纳米工艺努力的方向。本项目拟利用多物理场调制电子相分离体系LaxSr1-xMnO3，PrxCa1-xMnO3形成金属（铁磁相）-绝缘体（反铁磁）多种有序相共存的不同界面，结合团簇的多界面特点基于在受限空间中的强界面耦合作用实现核壳团簇器件磁电输运性能的调控。首先探索界面耦合作用对不同团簇组分、团簇母相磁结构、核壳厚度、受限空间尺度下性能调控和相变调控规律。然后从磁畴翻转动力学角度揭示界面耦合对团簇自旋序、电子结构调控的机制进而指导团簇器件和新材料设计。本项目为介观尺度团簇器件的设计和性能调控开启新途径。

复杂锰氧化物团簇复合器件在电子信息、磁性相变、传感器、绿色能源方面有广阔的应用前景。以团簇锰氧化物复合体系为依托，设计出单相Fe-Fe3O4核壳团簇电子开关器件，为介观尺度团簇器件的设计和性能调控开启新途径；完成NiFe团簇异质结高空间分辨柔性磁探测器制造，并在FeCo团簇中建立了界面耦合尺寸方程；紫外激光辐射双钙钛矿锰氧化物形成人造点缺陷体系中获得正负磁卡效应，在层状Bi基电介质中引入离子插层获得高储能密度材料，拓宽铁电体物理研究范畴；同时发展和丰富了非对称掺杂在铁电介质Bi5Ti3FeO15基态极性序、锰氧化物BiMn2O5体系中反铁磁基态的调控机制和掺杂原则，现推广到Lu1-xSrxMnO3体系中进行多铁性设计；提出极性序梯度的概念，并在层状电介质体系中获得实验观察。在NiCu合金团簇研究中获得正/负磁电阻效应切换机制和反常磁结构，在团簇电子学上有很好的应用前景。这些研究成果不仅在基础研究方面有一定的学术价值，而且为探索新型功能材料提供重要参考。