Magnetic insulators are important materials for a range of next-generation memory and spintronic applications. Structural constraints in this class of devices generally require a clean heterointerface that allows effective magnetic coupling between the insulating layer and the conducting layer. However, there are relatively few examples of magnetic insulators that can be synthesized with surface qualities that would allow these smooth interfaces and precisely tuned interfacial magnetic exchange coupling, which might be applicable at room temperature. In this work, we demonstrate an example of how the configurational complexity in the magnetic insulator layer can be used to realize these properties. The entropy-assisted synthesis is used to create single-crystal (Mg0.2Ni0.2Fe0.2Co0.2Cu0.2)Fe2O4 films on substrates spanning a range of strain states. These films show smooth surfaces, high resistivity, and strong magnetic responses at room temperature. Local and global magnetic measurements further demonstrate how strain can be used to manipulate the magnetic texture and anisotropy. These findings provide insight into how precise magnetic responses can be designed using compositionally complex materials that may find application in next-generation magnetic devices.
Systematic integration of atomistic simulations with phase-field modeling is presented for quantitative predictions of cellular growth and solute trapping during solidification of alloys for solidification velocities relevant to additive manufacturing. For parametrization of the phase-field model, molecular dynamics simulations are utilized as an alternative to complex experiments to obtain the anisotropic crystal-melt interface free energy, kinetic coefficient, and diffusive interface velocity. The accuracy of this integrated model is tested for rapid solidification of Ti-3.4at.%Ni alloy. The predicted solute trapping of the proposed phase-field model is comparable with the continuous growth model for solidification velocities of additive manufacturing. The predicted primary dendritic arm spacing is weakly dependent on the diffuse interface width enabling simulations in larger length scales. The concentration profile and partition coefficient obtained from both two-and three-dimensional phase-field simulations are comparable to the results of Kurz-Fisher's analytical and continuous growth models, respectively. Unlike other computational models for rapid solidification, the proposed model enables predictions completely based on computations without fitting to experiments.