铁磁/铁电异质结构中低维磁性的电场调控

Recently, multiferroic materials have attracted much attention for people working on materials, physics and device because these materials are not only related to some importance issues, such as the coupling between the ferromagnetic order and ferroelectric order, but also important for applications in information storage. So far, however, single-phase multiferroic materials are rare at room temperature and the converse magnetoelectric effects are typically too small to be useful. The use of artificial two-phase systems consisting of ferromagnetic (FM) and ferroelectric (FE) materials, especially various room temperature FM and FE materials, serves as an alternative approach to achieve electric-field control of magnetism and has been widely studied in recent years due to their remarkable magnetoelectric coupling, especially the electric-field control of magnetism. We plan to fabricated confined (2D and 3D) magnetic structure and multilayer structure on FE substrates via film growth and photolithography. Study the behavior of electric-field control of magnetism in these structures, uncover the mechanism of electric-field control of magnetism in the confined (1D, 2D and 3D) magnetic structure and multilayer structure, and realize electric-field control of magnetism and tunneling magnetoresistance in the magnetic tunnel junction/FE structures.

多铁材料不仅涉及磁性和铁电序间的耦合等重要的科学问题，而且在信息存储等方面具有潜在的巨大应用前景，是近年来材料、物理和器件等领域的研究热点。目前，室温下单相多铁材料很少，并且反磁电耦合系数太小，这使得其在应用方面难有作为。铁磁/铁电复合材料由于有很多室温下的性能优异的铁磁和铁电材料可以选择，并且其相互间的耦合，特别是电场对磁性的显著调控，因此，是多铁材料研究中的重要方向。我们拟通过薄膜生长和微纳加工方法得到在铁电衬底上不同维度受限（二维和三维）的人工磁结构和多层膜结构，研究电场对其磁性调控的规律，从而揭示铁磁/铁电异质结构中电场对受限磁性调控的物理机制，并实现电场对磁隧道结等器件性能的调控。

多铁材料不仅涉及磁性和铁电序间的耦合等重要的科学问题，而且在信息存储等方面具有潜在的巨大应用前景，是近年来材料、物理和器件等领域的研究热点。目前，室温下单相多铁材料很少，并且反磁电耦合系数太小，这使得其在应用方面难有作为。铁磁/铁电复合材料由于有很多室温下的性能优异的铁磁和铁电材料可以选择，并且其相互间的耦合，特别是电场对磁性的显著调控，因此，是多铁材料研究中的重要方向。本项目研究了基于磁电耦合效应的电场对磁隧道结隧道磁电阻的巨大的非挥发调控；电场对微米CoFeB圆盘/PMN-PT磁性调控；CoFeB/PMN-0.2PT多铁异质结构中反常的电控磁行为及对称破缺；多铁异质结Fe/PMN-PT中磁晶各向异性对磁电耦合行为影响；电场对(Co/Pt)3/ PMN-PT多层膜界面磁各向异性及自旋重取向转变的调控；空间分辨的不同类型铁电畴翻转对CoFeB/PMN-xPT磁性的影响等。我们观察到了一些新的现象，得到了电场对磁性调控的规律，揭示了相关的机制。本工作对于低功耗自旋电子学的应用及新型“电写磁读”型低功耗随机存储器具有重要的参考价值。