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PrCo 5 particles exhibit promising application potentials in fabricating high-performance permanent magnets and nanocomposite magnets. In view of this, we employ a bottom up strategy to fabricate highly anisotropic PrCo 5 particles. The synthesis process of PrCo 5 particles involved mainly two steps, (i) preparation of precursor that contains a mixture of amorphous Pr(OH) 3 and crystalline Co(OH) 2 (ii) Using a calciothermic-reduction, the precursor mixture has converted into PrCo 5 particles, which are similar to the traditionally prepared SmCo 5 particles. The obtained PrCo 5 particles mostly single crystal with an average size from 200 nm to 800 nm. The strong magnetic anisotropy and excellent magnetic properties, especially a high degree of grain alignment and large remanance ratio (M r /M 100kOe) leads to a large maximum energy product at room temperature. Therefore, the coercivity of 8.56 kOe, M r /M 100kOe of 0.80 and the maximum energy product of 12.64MGOe were achieved in aligned PrCo 5 particles. The results suggest a pathway for the development of nanocomposite magnets with an enhanced energy product. • Highly anisotropic PrCo 5 assembly of crystals have been synthesized. • The PrCo 5 particles exhibit the high coercivity of 8.56 kOe. • The maximum energy product of 12.64MGOe is obtained. [ABSTRACT FROM AUTHOR]

Highly anisotropic SmCo 5 single crystal particles are promising candidates for high-density data storage and building nanocomposite permanent magnets with large maximum energy product. Previously, nanocrystalline SmCo 5 particles obtained by calciothermic reduction exhibit low magnetic energy product due to magnetic isotropy caused by severely agglomerated equiaxial particles. In this study, we report a new strategy to fabricate highly anisotropic SmCo 5 nanochips by reductive annealing of precursors with a special designed morphology. The precursors containing single crystal Co(OH) 2 nanoflakes and crystalline Sm(OH) 3 nanorods were synthesized by a hydrothermal process, and converted into SmCo 5 nanochips by subsequent thermal reduction, during which the Co(OH) 2 nanoflakes facilitate the formation of SmCo 5 nanochips as a template and Sm(OH) 3 nanorods help to maintain the hexagonal morphology and single crystal nature. The SmCo 5 nanochips exhibit strong magnetic anisotropy and excellent room temperature magnetic properties with a remanence of 7.7 kG, coercivity of 19.3 kOe, and maximum energy product of 14.4 MGOe, which is the highest recorded value for chemical synthesized nanostructured SmCo 5 particles. [ABSTRACT FROM AUTHOR]

Cobalt nanowires were synthesized by reduction of carboxylate salts of Co in 1, 2-butanediol using a solvothermal chemical process. These nanowires crystallize with the hcp structure and the growth axis is parallel to the crystallographic c-axis. The morphology of the nanowires that prepared with mechanical stirring during earlier stage of the reaction process exhibits a smaller averaged aspect ratio but narrow size distribution. The assembly of the nanowires that prepared with mechanical stirring shows almost same coercivity and remanent magnetization but 59% increase of magnetic energy product. This remarkable improvement of energy product has been further understood by micromagnetic simulations. The magnetic performance at variant temperatures of Co nanowires has also been presented. These ferromagnetic nanowires could be new ideal building blocks for permanent magnets with high performance and high thermal stability. [ABSTRACT FROM AUTHOR]

Ferromagnetic metallic Cobalt nanowires are synthesized by the reduction of carboxylate salts of Co in 1, 2-butanediol using a solvothermal chemical process. In this process, the size and shape of the nanocrystals can be controlled via reaction parameters such as surfactant ratio, precursor concentration, and the temperature ramp. Synthesized Co nanocrystals exhibit the hexagonally close-packed phase favored the growth of anisotropic particles and the (002) crystalline direction is along the long axis of the nanowires. By varying the catalyst concentration in proper range, the effect of synthetic parameters on controlling Co nanoparticles with different length of 50 - 700 nm was systematically studied. Magnetic measurements and TEM images of the Cobalt nanowires indicate that the coercivity of the Co nanowires depends substantially on the morphology. The obtained highest coercivity of 8.4 kOe can be attributed to their small mean diameter and high crystallinity of nanowires for 200 - 300 nm. [ABSTRACT FROM AUTHOR]