Spin-wave spectroscopy of individual ferromagnetic nanodisks

Abstract

An original spatially resolved approach is demonstrated for spin-wave spectroscopy of individual circular magnetic elements. It allows for the deduction of the saturation magnetization and the exchange stiffness of the material with high precision.

Spin-wave eigenmodes in direct-write 3D nanovolcanoes

“…34,35 Given FEBID's lateral resolution down to 10 nm and its versatility regarding the substrate material, FEBID appears as a promising nanofabrication technology for 3D magnonics. 36 Here, we investigate the spin-wave eigenmodes in individual direct-write Co-Fe nanovolcanoes by spin-wave resonance (SWR) spectroscopy 37,38 and analyze the experimental data with the aid of micromagnetic simulations. We reveal that the microwave response of the nanovolcanoes essentially differs from the sum of the microwave responses of their constituent 2D elements-nanorings and nanodisks.…”

“…M s and A values correspond to those for equivalent diameter Co-Fe nanodisks. 37 The frequencies of the modes D1-D3, R1, and R2 are calculated at 1.7 T for NV1000/700 and NV600/400 and at 1.2 T for all other samples. Upper part: Nanovolcanoes studied experimentally and by micromagnetic simulations.…”

“…Finally, a fast Fourier transform was used to extract the normalized frequency spectra and the spatial dependences of the spin-wave eigenmodes. In the simulations, we used the saturation magnetization M s and exchange stiffness A values deduced for the disks with the same diameters and deposited with the same FEBID parameters 37 (Table I) and the assumed gyromagnetic ratio of c=2p ¼ 3:05 MHz/Oe. 50 The decrease in M s and A with the decrease in the disk diameter from 1 lm to 300 nm is associated with a decrease in the [Co 3 Fe] content from 80 6 3 at.…”

Control of Structural and Magnetic Properties of Polycrystalline Co2FeGe Films via Deposition and Annealing Temperatures

“…The ‘dead’ magnetic layer associated with native surface oxide and crystallite boundaries in nanostructured films were not considered in the calculations because the estimation of their actual ratio is speculative. Second, only the 1st order standing spin wave was observed in the experiment leading to limitations in applicability of the Equation (3) [ 47 ].…”

Writing 3D Nanomagnets Using Focused Electron Beams

“…Covering a wide frequency range from sub-GHz to tens of THz and being free from the translational motion of electrons and the associated Joule heat, spin waves possess great potential for realizing novel, highly efficient wave-based computing concepts [ 139 ]. In this regard, FEBID, whose potential for magnonic applications has been demonstrated in a few proof-of-concept experiments [ 71 , 140 , 141 ], can offer unique features which go beyond the rich instrumentation of traditional fabrication techniques employed in magnonics.…”