Interacting Stoner–Wohlfarth behavior in hysteresis curves of Sm(CoFeCuZr)z magnets

Microstructural changes during the slow-cooling annealing of nanocrystalline SmCo 2:17 type magnets

“…H is the applied field, H A is the anisotropy field, M is magnetization and M S is the magnetization of saturation and (1/d) is the CLC particle interaction parameter [10,11]. h SW refers to the isotropic hysteresis presented by Stoner and Wohlfarth for phases with uniaxial anisotropy [15].…”

“…h SW refers to the isotropic hysteresis presented by Stoner and Wohlfarth for phases with uniaxial anisotropy [15]. In previous studies, it was found that (1/d) parameter is always positive [10,11], and this implies that the observed remanence was less than the half of saturation (M S ) predicted by the original SW model [15]. Fig.…”

“…The microstructural changes during the last annealing steps (iii) and (iv) are re-evaluated in the present study using Rietveld analysis of X-ray Diffraction data, SEM (scanning electron microscope)-FEG (field emission gun) images, and also with modeling of the hysteresis curves with the Stoner-Wohlfarth-Callen-Liu-Cullen (SW-CLC) model [10][11][12][13], which gives relevant information concerning coercivity mechanisms. It is also employed a diffusion-based microstructural model able to make helpful predictions concerning change of chemical composition of the nanocrystalline phases along the heat treatment [14].…”

“…These possible interactions maybe either exchange coupling or magnetostastic coupling. The CLC modification changes the shape of the hysteresis curve similarly to an inverse demagnetizing field [10,11]. submitted to (i) a solubilization heat treatment at 1175°C for 4 h, (ii) quenching in water, (iii) reheated up to 820°C, remaining at this temperature for 7 h, and (iii) were then slow cooled (À1°C/min) to 400°C, and remaining for an additional 24 h at 400°C.…”

Quantifying magnetic anisotropy dispersion: Theoretical and experimental study of the magnetic properties of anisotropic FeCuNbSiB ferromagnetic films

“…The more general anisotropic case has been also received attention and several very interesting works on this issue can be found in literature. This is the case of studies on the influence of the function f (ψ) on the magnetic parameters of the magnetization curve [22,23], description of systems with biaxial anisotropy [29,30], with distribution of magnetic moment of particles [31] or of anisotropy strength [24,25,32,33], as well as investigations of systems considering interactions between the particles through a mean field [24,25,[34][35][36][37] or taking into account temperature effects [38][39][40][41]. On the other hand, just a few studies compare numerical calculations and experimental results, probably due to the fact that the determination of the appropriate magnetic free energy density can represent a hard task.…”