Hohenberger Stefan, Jochum Johanna K, Van Bael Margriet J, Temst Kristiaan, Patzig Christian, Höche Thomas, Grundmann Marius, Lorenz Michael
Felix-Bloch-Institut für Festkörperphysik, Universität Leipzig, Linnéstraße 5, D-04103 Leipzig, Germany.
Quantum Solid State Physics, Celestijnenlaan 200D, B-3001 Leuven, Belgium.
Materials (Basel). 2020 Jan 2;13(1):197. doi: 10.3390/ma13010197.
Combining various (multi-)ferroic materials into heterostructures is a promising route to enhance their inherent properties, such as the magnetoelectric coupling in BiFeO3 thin films. We have previously reported on the up-to-tenfold increase of the magnetoelectric voltage coefficient α ME in BaTiO3-BiFeO3 multilayers relative to BiFeO3 single layers. Unraveling the origin and mechanism of this enhanced effect is a prerequisite to designing new materials for the application of magnetoelectric devices. By careful variations in the multilayer design we now present an evaluation of the influences of the BaTiO3-BiFeO3 thickness ratio, oxygen pressure during deposition, and double layer thickness. Our findings suggest an interface driven effect at the core of the magnetoelectric coupling effect in our multilayers superimposed on the inherent magnetoelectric coupling of BiFeO3 thin films, which leads to a giant α ME coefficient of 480 V c m -1 Oe-1 for a 16 × (BaTiO3-BiFeO3) superlattice with a 4 . 8 nm double layer periodicity.
将各种（多）铁电材料组合成异质结构是增强其固有特性的一条有前途的途径，比如增强BiFeO₃薄膜中的磁电耦合。我们之前报道过，相对于BiFeO₃单层，BaTiO₃-BiFeO₃多层膜中的磁电电压系数αME提高了多达10倍。揭示这种增强效应的起源和机制是设计用于磁电器件应用的新材料的先决条件。通过精心改变多层膜设计，我们现在对BaTiO₃-BiFeO₃厚度比、沉积过程中的氧气压力和双层厚度的影响进行了评估。我们的研究结果表明，在我们的多层膜中，磁电耦合效应的核心存在界面驱动效应，该效应叠加在BiFeO₃薄膜的固有磁电耦合之上，对于具有4.8nm双层周期的16×（BaTiO₃-BiFeO₃）超晶格，这导致了480V cm⁻¹ Oe⁻¹的巨大αME系数。
