Micromagnetic investigation of domain and domain wall evolution through the spin-reorientation transition of an epitaxial NdCo₅film

Abstract

The domain pattern and the domain wall microstructure throughout the spin-reorientation transition of an epitaxial NdCo 5 thin film are investigated by micromagnetic simulations. The temperaturedependent anisotropy constants K 1 and K 2 , which define the anisotropy energy term in the model, are chosen to reflect the easy axis-easy cone-easy plane spin-reorientation transition observed in epitaxial NdCo 5 thin films. Starting at the high-temperature easy c-axis regime, the anisotropy constants are changed systematically corresponding to a lowering of the temperature of the system. The character of the domain walls and their profiles are analysed. The calculated domain configurations are compared to the experimentally observed temperature-dependent domain structure of an in-plane textured NdCo 5 thin film.

Interaction of gapless spin waves and a domain wall in an easy-cone ferromagnet

“…( 4)]. We numerically obtained the velocity by using the material parameters of NdCo 5 given by lattice constant a = 0.5 nm, saturation magnetization M s = 1.1 × 10 6 A/m, A = 1.1 × 10 −11 J/m, K = 2.4 × 10 6 J/m 3 , K ′ = 1.6×10 6 J/m 3 , and thereby κ = 0.67 [28][29][30][31]. Here in τ and F , the probabilities T (ϵ) and R(ϵ) can be affected by the presence of magnon damping in accordance with the fluctuation-dissipation theorem [44].…”

“…Recent technology to fabricate easy-cone magnets has advanced significantly, increasing the feasibility of easycone magnets for experimental studies and technological applications. The example materials include Co/Pt, Ta/Co 60 Fe 20 B 20 /MgO, (Cr 0.9 B 0.1 )Te, and NdCo 5 [25][26][27][28][29][30][31]. However, despite the aforementioned unique features of easy-cone systems compared to easy-axis systems, the spin-wave properties, the dynamics of solitons such as a DW, and their interactions in easy-cone magnets have been studied little.…”

Interaction of gapless spin waves and a domain wall in an easy-cone ferromagnet

“…( 4)]. We numerically obtained the velocity by using the material parameters of NdCo 5 given by lattice constant a = 0.5 nm, saturation magnetization M s = 1.1 × 10 6 A/m, A = 1.1 × 10 −11 J/m, K = 2.4 × 10 6 J/m 3 , K ′ = 1.6×10 6 J/m 3 , and thereby κ = 0.75 [28][29][30][31]. Figure 3(b) shows the velocity of the thermally driven DWs in NdCo 5 as a function of T avg with ∆T = 0.1T avg .…”

“…Recent technology to fabricate easycone magnets has advanced significantly, increasing the feasibility of easy-cone magnets for experimental studies and technological applications. The example materials include Co/Pt, Ta/Co 60 Fe 20 B 20 /MgO, (Cr 0.9 B 0.1 )Te, and NdCo 5 [25][26][27][28][29][30][31]. However, despite the aforementioned unique features of easy-cone systems compared to easyaxis systems, the spin-wave properties, the dynamics of solitons such as a DW, and their interactions in easy-cone magnets have been studied little.…”

Spin-reorientation critical dynamics in the two-dimensional XY model with a domain wall

“…In recent experiments, spin configurations with non-180 • domain walls have also been found, but relevant theoretical explanations are still primitive [8,[36][37][38]. Very recently, a spin-reorientation transition has been revealed in epitaxial NdCo 5 thin film with temperature-dependent domainwall orientations [39]. However, the dynamic properties have not been touched yet.…”