Field-controlled ultrafast magnetization dynamics in two-dimensional nanoscale ferromagnetic antidot arrays

Abstract

Ferromagnetic antidot arrays have emerged as a system of tremendous interest due to their interesting spin configuration and dynamics as well as their potential applications in magnetic storage, memory, logic, communications and sensing devices. Here, we report experimental and numerical investigation of ultrafast magnetization dynamics in a new type of antidot lattice in the form of triangular-shaped Ni80Fe20 antidots arranged in a hexagonal array. Time-resolved magneto-optical Kerr effect and micromagnetic simulations have been exploited to study the magnetization precession and spin-wave modes of the antidot lattice with varying lattice constant and in-plane orientation of the bias-magnetic field. A remarkable variation in the spin-wave modes with the orientation of in-plane bias magnetic field is found to be associated with the conversion of extended spin-wave modes to quantized ones and vice versa. The lattice constant also influences this variation in spin-wave spectra and spin-wave mode profiles. These observations are important for potential applications of the antidot lattices with triangular holes in future magnonic and spintronic devices.

Magnetization dynamics of nanoscale magnetic materials: A perspective

“…Bragg diffraction of SW from ADL and ensuing MBG 116 , high-symmetry magnonic modes in perpendicularly magnetized ADL 117 , and complete MBG for magnetostatic forward volume waves in 2D ADL 118 . Subsequently external and internal control of SW modes in ADL started by varying lattice constant 119 , antidot shape 120 , lattice symmetry 121 , base material 122,123 , bias field strength and orientation 114,124 . Furthermore, several interesting phenomena such as mode conversion 125 , mode crossover and mode hopping 126 , mode softening 127 , as well as the formation of magnonic mini band 128 have been reported.…”

Tunability of Domain Structure and Magnonic Spectra in Antidot Arrays of Heusler Alloy

“…In addition, there are few reports on antidot arrays with the anisotropic structures like triangular and diamond shaped holes which may significantly modify the internal field distribution in the vicinity of the holes leading to further modifications of the SW spectra of such systems. [16,31,32] In this present work we have chosen Co 2 Fe 0.4 Mn 0.6 Si (CFMS) thin films and their antidot arrays for the investigation of SW dynamics. To the best of our knowledge, there are no reports yet for the study of magnetization dynamics in antidot arrays of similar materials.…”

“…steeper dispersion). [16,17] The edges of the holes in the antidot arrays quantize the SW modes and modulate internal magnetic field periodically due to the demagnetizing effect. [16] Over the last decade several works have been reported on the control of SW dynamics in MAL arrays by varying the antidot architecture.…”

“…[16,17] The edges of the holes in the antidot arrays quantize the SW modes and modulate internal magnetic field periodically due to the demagnetizing effect. [16] Over the last decade several works have been reported on the control of SW dynamics in MAL arrays by varying the antidot architecture. [18][19][20][21][22][23][24] Further the most desired characteristics of a material for magnonic based applications are low magnetic damping, high saturation magnetization, high curie temperature, long spin wave propagation distance, etc.…”

Magnetic properties of Fe3O4 antidot arrays synthesized by AFIR: atomic layer deposition, focused ion beam and thermal reduction

“…Magnetic antidots, magnetic thin films with periodic arrays of holes, are currently an important topic for both the fundamental understanding of low-dimensional magnetism and a broad range of applications, such as a new generation of electronic devices [ 1 ], sensors [ 2 ], ultra-high density recording media – due to the absence of the superparamagnetic limit as there are no isolated magnetic islands – [ 3 ], and magnonics and spintronic devices [ 4 – 5 ]. The presence of the ordered non-magnetic holes induces a demagnetization field distribution that changes the magnetization switching mechanisms [ 6 ], acting as pinning centers for domain walls [ 7 ], enhancing coercivity compared to that of the continuous film [ 8 – 12 ], and affecting the magnetic properties of the film [ 13 – 19 ].…”