Holländer Rasmus B, Müller Cai, Schmalz Julius, Gerken Martina, McCord Jeffrey
Institute of Materials Science, Kiel University, Kiel, 24143, Germany.
Institute of Electrical and Information Engineering, Kiel University, Kiel, 24143, Germany.
Sci Rep. 2018 Sep 17;8(1):13871. doi: 10.1038/s41598-018-31689-8.
We report on the direct observation of spin wave and elastic wave emission from magnetic domain walls in ferromagnetic thin films. Driven by alternating homogeneous magnetic fields the magnetic domain walls act as coherent magnetisation wave sources. Directional and low damped elastic waves below and above the ferromagnetic resonance are excited. The wave vector of the magnetoelastically induced acoustic waves is tuned by varying the excitation frequency. The occurrence of elastic wave emission is proved by a combination of micromagnetic and mechanical finite element simulations. Domain wall emitted magnetostatic surface spin waves occur at higher frequencies, which characteristics are confirmed by micromagnetic simulations. The distinct modes of magnetisation wave excitation from micromagnetic objects are a general physical phenomenon relevant for dynamic magnetisation processes in structured magnetic films. Magnetic domain walls can act as reconfigurable antennas for spin wave and elastic wave generation. The wave orientation can be controlled separately via the domain wall orientation for elastic waves and via magnetization orientation for magnetostatic surface spin waves.
我们报告了对铁磁薄膜中磁畴壁发射的自旋波和弹性波的直接观测。在交变均匀磁场的驱动下，磁畴壁充当相干磁化波源。在铁磁共振频率上下激发了定向且低阻尼的弹性波。通过改变激发频率来调节磁弹致声波的波矢。微磁学和机械有限元模拟相结合证明了弹性波发射的存在。磁畴壁发射的静磁表面自旋波出现在更高频率，其特性通过微磁学模拟得到证实。从微磁学对象激发磁化波的不同模式是一种与结构化磁性薄膜中的动态磁化过程相关的普遍物理现象。磁畴壁可作为用于产生自旋波和弹性波的可重构天线。弹性波的波取向可通过畴壁取向单独控制，静磁表面自旋波的波取向可通过磁化取向单独控制。
