The precise control of individual components in multicomponent nanostructures is crucial to realizing their fascinating functionalities for applications in electronics, energy-conversion devices, and biotechnologies. However, this control remains particularly challenging for bulk, multicomponent nanomaterials because the desired structures of the constitute components often conflict. Herein, a strategy is reported for simultaneously controlling the structural properties of the constituent components in bulk multicomponent nanostructures through layered structural design. The power of this approach is illustrated by generating the desired structures of each constituent in a bulk multicomponent nanomaterial (SmCo + FeCo)/NdFeB, which cannot be attained with existing methods. The resulting nanostructure exhibits a record high energy density (31 MGOe) for this class of bulk nanocomposites composed of both hard and soft magnetic materials, with the soft magnetic fraction exceeding 20 wt%. It is anticipated that other properties beyond magnetism, such as the thermoelectric and mechanical properties, can also be tuned by engineering such layered architectures.

Nanoparticle self-assembly enables the generation of complex ordered nanostructures with enhanced properties or new functionalities. However, the ordering is often limited to the micrometer scale with chemical strategies due to the relative weak supramolecular interactions that govern the self-assembly process. Here a physical strategy via temperature-gradient-assisted self-assembly is reported to create three-dimensional (3D) macroscopic ordered nanocomposites with different gradient variations in grain size, constituent content, and crystal orientation. The resulting α-Fe/Pr2Fe14B ordered nanostructure with reverse gradients in both the grain size and α-Fe content exhibits a record-high energy density of about 25 MGOe for isotropic α-Fe/Pr2Fe14B systems, approximately 130% higher than that of its disordered counterpart. Both experiments and micromagnetic simulations demonstrate that creating ordered nanostructures is an alternative approach to develop high-performance permanent-magnet materials. Our findings make a significant step toward creating 3D macroscopic ordered nanostructures and will stimulate the development of ordered nanomaterials.

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For bulk SmCo3 system hard-soft magnetic nanocomposites, it remains a challenge to fabricate an anisotropic magnet by forming a strong texture for the nanocrystalline SmCo3 phase. In this paper, we report the fabrication of a bulk anisotropic SmCo3/Fe(Co) nanocomposite magnet with a strong (00 l) texture for the SmCo3 phase and a small grain size of 21 nm for the Fe(Co) phase. Good results were achieved by controlling the nucleation and growth of the nanocrystals from the amorphous matrix using large stress and strain. The synthesized magnet exhibited a high-energy product of 17.0 MGOe, which was 26% larger than the reported highest value of 13.5 MGOe for SmCo3-based nanocomposites and 314% higher than 4.1 MGOe for the corresponding pure SmCo3 magnets. Moreover, these magnets possessed small remanence and coercivity temperature coefficients of α = −0.018%/°C and β = −0.24%/°C, which were much lower than those α = −0.14%/°C and β = −0.31%/°C for pure SmCo3 magnets and α = −0.073%/°C and β = −0.30%/°C for SmCo3/Fe(Co) isotropic nanocomposite. These findings are an important step toward the practical application of the SmCo3-based nanocomposite.