Shape- and Interface-Induced Control of Spin Dynamics of Two-Dimensional Bicomponent Magnonic Crystals

Abstract

Controlled fabrication of periodically arranged embedded nanostructures with strong interelement interaction through the interface between the two different materials has great potential applications in spintronics, spin logic, and other spin-based communication devices. Here, we report the fabrication of two-dimensional bicomponent magnonic crystals in form of embedded Ni80Fe20 nanostructures in Co50Fe50 thin films by nanolithography. The spin wave (SW) spectra studied by a broadband ferromagnetic resonance spectroscopy showed a significant variation as the shape of the embedded nanostructure changes from circular to square. Significantly, in both shapes, a minimum in frequency is obtained at a negative value of bias field during the field hysteresis confirming the presence of a strong exchange coupling at the interface between the two materials, which can potentially increase the spin wave propagation velocity in such structures leading to faster gigahertz frequency magnetic communication and logic devices. The spin wave frequencies and bandgaps show bias field tunability, which is important for above device applications. Numerical simulations qualitatively reproduced the experimental results, and simulated mode profiles revealed the spatial distribution of the SW modes and internal magnetic fields responsible for this observation. Development of such controlled arrays of embedded nanostructures with improved interface can be easily applied to other forms of artificial crystals.

All-optical detection of the spin Hall angle inW/CoFeB/SiO2heterostructures with varying thickness of the tungsten layer

“…The exciting new frontier of spintronics [1] and magnonics [2,3] research is driven by the need of utilizing spin-orbit (SO) effect for obtaining pure spin current [4]. An important aspect of improving the performance of the device is to minimize Joule heating, which requires fundamentally pure spin current [4,5].…”

Dynamic and static properties of stadium-shaped antidot arrays

“…Numerical studies on the dynamic susceptibility of antidot arrays have shown that by modifying the hole density or hole geometry, it is possible to achieve a reasonable degree of control over the number of resonant peaks, their amplitude and their position 53 , 54 . In fact, it has been reported that antidot arrays with holes of different shape and size substantially modify the spin wave spectra of these systems 55 – 57 , establishing the geometrical variation of the antidots as the key for the tunability of spin wave structures. Furthermore, not only the shape and density of the antidot arrays play an important role in the dynamic properties of these structures, but also the lattice ordering and its symmetry have proven to be a feasible way to control and modulate the spin wave spectra 57 – 59 .…”

Influence of nonmagnetic dielectric spacers on the spin-wave response of one-dimensional planar magnonic crystals

“…In the experimental realization of bi-component MCs [21][22][23] , the interfaces between layers can suffer from oxidation, and so, a significant change of magnetic properties near the edges can be expected. This is especially important in the case of ferromagnetic metals because of arXiv:1905.11016v2 [cond-mat.mes-hall] 17 Jul 2019 their high reactivity with oxygen, 24 giving rise to oxides displaying paramagnetic or antiferromagnetic properties at temperatures above and below the Neel temperature, respectively.…”