Search

The morphotropic phase boundary (MPB) has been utilized extensively in ferroelectrics and recently been extended to ferromagnets, especially for the magnetostrictive materials. Here, guided by phenomenological theories and phase-field simulations, we proposed a design strategy for obtaining the ultrasensitive magnetoelastic response at the pre-transitional rhombohedral side of ferromagnetic MPB, by further flattening the energy landscape while maintaining large intrinsic magnetostriction. To validate this, we judiciously introduced the light-rare-earth-based Tb 0.1 Pr 0.9 system to the Co-doped Tb 0.27 Dy 0.73 Fe 2 alloy, as Tb 0.1 Pr 0.9 is an anisotropy compensation system with large intrinsic strains and the transition metal dopant of Co tends to optimize the magnetostriction. Phase-field modeling was used to determine the detailed magnetic domain evolution of the investigated multi-component Laves phase compounds, the results of which were compared with experimental results. At room temperature, an ultrahigh magnetoelastic response d 33 was found in Tb 0.253 Dy 0.657 Pr 0.09 (Fe 0.9 Co 0.1) 2 recompensation system especially at low fields, which is superior to that of the commercial Tb 0.27 Dy 0.73 Fe 2 (Terfenol-D) polycrystal. The ultrahigh magnetostrictive sensitivity, together with low raw material cost makes it one of the strongest candidates for magnetostriction applications. [ABSTRACT FROM AUTHOR]

Superconductors and ferromagnets are highly non-compatible materials due to the natures of their respective electronic states. But when artificially brought together, they develop interesting characteristics, one of which, vortex clustering, is discussed here in this paper. Phase-field and micromagnetic simulations are performed to investigate the superconductor and ferromagnet bilayer, respectively. The ferromagnet with uniaxial anisotropy is observed to develop the maze domain, whereas the superconductor subjected to the influence of the ferromagnetic stray field displays a vortex pattern. Clustered vortices in superconductors at certain locations are observed to be precisely located over magnetic domain bifurcations. The enhanced out-of-plane stray field at bifurcations around the curved domain walls and the convergent Lorentz force due to screening currents in superconductor are attributed to the formation of clusters at bifurcation sites. Segregation of the inter-vortex spacing between straight and bifurcated domain is clearly observed. More importantly, inter-vortex spacing is predicted to serve as a precise tool to map local ferromagnet domain shapes. [ABSTRACT FROM AUTHOR]