Control of Dynamics in Weak PMA Magnets

Abstract

We have recently shown that a hybrid magnetic thin film with orthogonal anisotropies presenting weak stripe domains can achieve a high degree of controllability of its ferromagnetic resonance. This work explores the origin of the reconfigurability through micromagnetic simulations. The static domain structures which control the thin film resonance can be found under a deterministic applied field protocol. In contrast to similar systems reported, our effect can be obtained under low magnetic fields. We have also found through simulations that the spin wave propagation in the hybrid is nonreciprocal: two adjacent regions emit antiparallel spin waves along the stripe domains. Both properties convert the hybrid in a candidate for future magnonic devices at the nanoscale.

Shaping Perpendicular Magnetic Anisotropy of Co2MnGa Heusler Alloy Using Ion Irradiation for Magnetic Sensor Applications

“…Overall, our results shed light on the underlying mechanisms that govern PMA in Co-based Heusler alloys and provide insights into how to manipulate the PMA for specific applications, such as by controlling the fluence/DPA values of the ion irradiation. With the parameters that we used, our results show that PMA reduces upon Ar irradiation, which is desirable for various applications, such as voltage-tunable sensors, magnetic memory that requires efficient magnetization switching using voltage-induced strain for high-density storage and low power consumption and spintronic devices where a reduced PMA may enhance the stability and controllability of the magnetic domains [21,22,117]. In a recent report, Gabor et al [111] studied CoFe-based Heusler alloys and found that a CoFe-rich interfacial layer promotes strong electronic hybridization between the metal and oxygen orbitals, leading to PMA.…”

Reconfigurable Magnonic Crystals Based on Imprinted Magnetization Textures in Hard and Soft Dipolar-Coupled Bilayers

“…For this purpose, we use a hybrid system consisting of a soft ferromagnetic film, which is dipolar-coupled to a hard layer exhibiting a stripe-domain pattern. 39 − 41 In previous studies, it has been shown that in this kind of hybrid system, the stripe-domain pattern from the hard magnetic layer is transferred to the soft one. 40 , 42 − 45 Interestingly, in the bilayer system with one layer possessing an out-of-plane component of the static magnetization, the static stray field affects both static and dynamic properties of the second medium.…”

“…Here we propose an approach, which enables us to avoid high damping of PMA materials while still harnessing the advantages of the magnetization texture for the efficient guiding and control of the SW propagation. For this purpose, we use a hybrid system consisting of a soft ferromagnetic film, which is dipolar-coupled to a hard layer exhibiting a stripe-domain pattern. − In previous studies, it has been shown that in this kind of hybrid system, the stripe-domain pattern from the hard magnetic layer is transferred to the soft one. ,− Interestingly, in the bilayer system with one layer possessing an out-of-plane component of the static magnetization, the static stray field affects both static and dynamic properties of the second medium . With this approach, we aim to combine the advantages of regular magnetization textures in PMA films with low-damping thin films, which can be used as an effective low-damping conduit of SWs to advance magnonics.…”

Tuning of Magnetic Damping in Y3Fe5O12/Metal Bilayers for Spin-Wave Conduit Termination

“…These long propagation distances pose questions on how to attenuate SWs when waveguides terminate without causing back reflection and signal interference. In micromagnetic simulations, this problem is solved by applying parabolic or exponential damping conditions near the edges of magnetic structures [30][31][32][33][34]. However, the experimental realization of this approach is not trivial.…”