Garten Lauren M, Staruch Margo L, Bussmann Konrad, Wollmershauser James, Finkel Peter
Material Science and Technology Division, U.S. Naval Research Laboratory, Washington D.C., Washington 20375, United States.
The School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States.
ACS Appl Mater Interfaces. 2022 Jun 8;14(22):25701-25709. doi: 10.1021/acsami.2c03869. Epub 2022 May 24.
Magnetoelectric materials present a unique opportunity for electric field-controlled magnetism. Even though strain-mediated multiferroic heterostructures have shown unprecedented increase in magnetoelectric coupling compared to single-phase materials, further improvements must be made before ultra-low power memory, logic, magnetic sensors, and wide spectrum antennas can be realized. This work presents how magnetoelectric coupling can be enhanced by simultaneously exploiting multiple strain engineering approaches in heterostructures composed of FeCo/Ag multilayers on (011) Pb(InNb)O-Pb(MgNb)O-PbTiO piezoelectric crystals. When grown and measured under strain, these heterostructures exhibit an effective converse magnetoelectric coefficient in the order of 10 s m: the highest directly measured, non-resonant value to-date. This response occurred at room temperature and at low electric fields (<2 kV cm). This large effect is enabled by magnetization reorientation caused by changing the magnetic anisotropy with strain from the substrate and the use of multilayered magnetic materials to minimize the internal stress from deposition. Additionally, the coercive field dependence of the magnetoelectric response under strain suggests contributions from domain-mediated magnetization switching modified by voltage-induced magnetoelastic anisotropy. This work highlights how multicomponent strain engineering enables enhanced magnetoelectric coupling in heterostructures and provides an approach to realize energy-efficient magnetoelectric applications.
磁电材料为电场控制磁性提供了独特的契机。尽管与单相材料相比，应变介导的多铁性异质结构已展现出磁电耦合前所未有的增强，但在实现超低功耗存储器、逻辑器件、磁传感器和广谱天线之前，仍需进一步改进。本文介绍了在由(011) Pb(InNb)O-Pb(MgNb)O-PbTiO压电晶体上的FeCo/Ag多层膜组成的异质结构中，如何通过同时利用多种应变工程方法来增强磁电耦合。当在应变条件下生长和测量时，这些异质结构展现出约10 s m量级的有效逆磁电系数：这是迄今为止直接测量到的最高非共振值。这种响应发生在室温及低电场（<2 kV cm）条件下。这种显著效应是由以下因素促成的：通过衬底应变改变磁各向异性导致的磁化重新取向，以及使用多层磁性材料来最小化沉积产生的内应力。此外，应变下磁电响应的矫顽场依赖性表明，电压诱导的磁弹性各向异性对畴介导的磁化翻转有贡献。本文强调了多组分应变工程如何在异质结构中实现增强的磁电耦合，并提供了一种实现节能磁电应用的方法。
