Gilbert Ian, Chavez Andres C, Pierce Daniel T, Unguris John, Sun Wei-Yang, Liang Cheng-Yen, Carman Gregory P
Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899.
Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, CA 90095.
Appl Phys Lett. 2016 Oct;109(16). doi: 10.1063/1.4965028. Epub 2016 Oct 17.
Strain-mediated thin film multiferroics comprising piezoelectric/ferromagnetic heterostructures enable the electrical manipulation of magnetization with much greater efficiency than other methods; however, the investigation of nanostructures fabricated from these materials is limited. Here we characterize ferromagnetic Ni nanostructures grown on a ferroelectric PMN-PT substrate using scanning electron microscopy with polarization analysis (SEMPA) and micromagnetic simulations. The magnetization of the Ni nanostructures can be controlled with a combination of sample geometry and applied electric field, which strains the ferroelectric substrate and changes the magnetization via magnetoelastic coupling. We evaluate two types of simulations of ferromagnetic nanostructures on strained ferroelectric substrates: conventional micromagnetic simulations including a simple uniaxial strain, and coupled micromagnetic-elastodynamic simulations. Both simulations qualitatively capture the response of the magnetization changes produced by the applied strain, with the coupled solution providing more accurate representation.
由压电/铁磁异质结构组成的应变介导薄膜多铁性材料能够比其他方法更高效地实现对磁化强度的电操控；然而，对由这些材料制成的纳米结构的研究却很有限。在此，我们利用带有极化分析的扫描电子显微镜（SEMPA）和微磁模拟，对生长在铁电PMN-PT衬底上的铁磁镍纳米结构进行了表征。镍纳米结构的磁化强度可以通过样品几何形状和外加电场的组合来控制，外加电场会使铁电衬底产生应变，并通过磁弹性耦合改变磁化强度。我们评估了在应变铁电衬底上的两种铁磁纳米结构模拟：包括简单单轴应变的传统微磁模拟，以及耦合微磁 - 弹性动力学模拟。两种模拟都定性地捕捉到了外加应变引起的磁化强度变化响应，其中耦合解提供了更准确的表述。
