Dy-free Nd-Fe-B anisotropic bonded magnets have superior features of high magnet properties of Nd₂Fe₁₄B compounds as well as shape flexibility and high electrical resistivity of bonded magnets. By taking advantage of such excellent features, they have been used in direct-current motors for automobiles, and recently, advances in molding technology have promoted the application of bonded magnets to direct-current brushless motors such as those for drones. With the electrification of automobiles toward the realization of energy-saving and decarbonized society, resource saving of motors is required. Here, motors using Dy-free Nd-Fe-B anisotropic bonded magnets can contribute to this requirement because of their high electrical resistivity, which reduces eddy currents and enables high-speed rotation and miniaturization. Therefore, the demand for such bonded magnets is expected to increase further. This paper describes manufacturing processes and recent developments of Dy-free Nd-Fe-B anisotropic bonded magnets and its future prospects.

Preparation methods for ceramic powders and surface modification methods of ceramic nanoparticles and nanosheets have been developed by combining knowledges and techniques inorganic chemistry and organic chemistry. Preparation of non-oxide ceramic powers by the use of inorganic and organometallic polymers as preceramic precursors has been developed for aluminum nitride and its composites using cage-type compounds with Al-N backbones. The use of preceramic precursors can also provide amorphous materials, whose use can realize the crystallization of high-pressure phases of metal nitrides under milder conditions. The preparation methods of metal oxide nanoparticles from metal chlorides using oxygen donors have also been developed for TiO₂ and Fe₃O₄. In addition, surface modification methods for metal oxide nanomaterials have been developed. It was demonstrated that the use of liquid-liquid biphasic systems was effective for surface modification of metal oxide nanoparticles and nanosheets. Surface modification of metal oxide nanosheets can also be achieved in a biphasic laminar flow in a microchannel. The development of regioselective surface modification of nanosheets using potassium hexaniobate trihydrate has realized the preparation of Janus nanosheets by using its unique structure. These achievements demonstrate the advantages of the combination of the methods of inorganic and organic chemistry for preparation of ceramic powders and their surface modification.

Ceramic powders and structures have been synthesized and manufactured by high-temperature firing. However, there are increasing expectations for the development of nanostructures that cannot be obtained by the firing method in search of higher functionality. In addition, cold crystallization is required from the viewpoints of energy saving, low environmental load, low cost, and hybridization with organic and metal materials. In this paper, I would like to introduce the development of powders and nanostructures by cold crystallization and morphological control for tin oxide, titanium dioxide, and zinc oxide. These powders and structures can be applied to various devices. A high spillover effect is expected in various fields. Furthermore, it is expected to contribute to SDGs (Sustainable Development Goals) in environmental fields such as energy saving and low environmental load.

Nanoporous metals having large surface area and unique bicontinuous structure have attracted much attention due to the excellent functional properties. Conventionally, nanoporous metals were prepared by dealloying in aqueous solution, which is a selective corrosion of less-noble component from the multicomponent alloy. However, the corrosion-based dealloying can only be applicable to synthesize noble nanoporous metals. We have recently developed an innovative dealloying method using liquid metal, termed as liquid metal dealloying, in which nanoporous metal is evolved in a liquid metal. We have successfully prepared various nanoporous less-noble metals in Ti, Nb, V, Cr, Fe, Si, and C which could not be synthesized in the aqueous solution. The developed nanoporous metals exhibited excellent performance as energy related materials. For example, nanoporous Si improved cyclic performance of the lithium-ion battery anode because the many open channels act as ideal volume expansion buffers. Nanoporous Nb significantly increased mass-specific capacitance in electrolytic capacitor because bicontinuous nanostructure was ideal for uniform formation of dielectric layer while keeping large surface area and conduction path. The liquid metal dealloying is a versatile technique that can be used to synthesize nanoporous less-noble metals, nano hetero composite materials and to modify the surface and composition of structural materials.