Engineering Bulk, Layered, Multicomponent Nanostructures with High Energy Density

Abstract

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.

Heterostructured materials: superior properties from hetero-zone interaction

“…For example, the trade-off in strength and ductility can be alleviated or even avoided in heterostructured metals [3,4]. Moreover, superior functional properties have also been realized in heterostructured functional materials [5][6][7][8]. These examples represent successful attempts to address classic challenges that cannot be solved via existing paradigms described in textbooks.…”

Heterostructures: new opportunities for functional materials

“…As a result, how to simultaneously obtain high magnetization and large coercivity becomes a key scientific problem and a fundamental challenge toward increasing the energy products of permanent-magnet materials. Recently, a conceptual strategy has been proposed to break the trade-off between magnetization and coercivity [19,20]. The basic idea is to introduce a heterostructure in permanent magnetic materials, in which one type of structures contribute to high magnetization via both the exchange coupling between soft-and hard-magnetic nanograins and the alignment of hard-magnetic phase, and the others contribute to large coercivity through impeding magnetization reversal.…”

“…The basic idea is to introduce a heterostructure in permanent magnetic materials, in which one type of structures contribute to high magnetization via both the exchange coupling between soft-and hard-magnetic nanograins and the alignment of hard-magnetic phase, and the others contribute to large coercivity through impeding magnetization reversal. With this strategy, great advances have been achieved toward high energy products in nanostructured magnets [19,20]. The resulting heterostructured magnets with NdFeB nanograin layers in a SmCo/FeCo nanostructured matrix exhibit an enhanced coercivity without reducing the remanence (B r ) ( Figure 3) [20], as compared to their corresponding homogeneous magnets, yielding a large energy product of 31 MGOe that outperforms the existing SmCobased hybrid nanostructured magnets and defeats, for the first time, the corresponding pure rare-earth magnets (Figure 3(c)).…”

“…With this strategy, great advances have been achieved toward high energy products in nanostructured magnets [19,20]. The resulting heterostructured magnets with NdFeB nanograin layers in a SmCo/FeCo nanostructured matrix exhibit an enhanced coercivity without reducing the remanence (B r ) ( Figure 3) [20], as compared to their corresponding homogeneous magnets, yielding a large energy product of 31 MGOe that outperforms the existing SmCobased hybrid nanostructured magnets and defeats, for the first time, the corresponding pure rare-earth magnets (Figure 3(c)). The achieved energy product is comparable to that (28-33 MGOe) of pure commercial SmCo magnets but with reduced rare-earth metals of 20-30 wt.%.…”

Beyond electrostatic modification: design and discovery of functional oxide phases via ionic-electronic doping

“…Energy related materials remain a central research topic due to the increasing demand for renewable energy and the proliferation of mobile devices. For energy applications, highly efficient materials are required in the process of energy harvesting, energy conversion, and energy storage [120][121][122][123][124][125][126], where control of structures is important in manipulating their functionalities and significant advances have been made [127][128][129]. In this section, efficiency increase through ion doping will be discussed in terms of oxygen evolution reaction (OER) electrocatalysis, solid oxide fuel cells (SOFCs), fuel storage, and thermoelectric properties.…”