• Journal of the Korean Ceramic Society
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• v.53 no.3
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• pp.367-375
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• 2016

A novel strategy for the synthesis of $CoSb_2$ nanoparticles is demonstrated via preparation of novel organometallic complexes. Hydrated cobalt oleate (CoOl) and non-hydrated antimony oleate (SbOl) complexes are synthesized as precursors. The $CoSb_2$ nanoparticles are prepared by hot injection, which involves thermolysis of CoOl and SbOl in a non-coordinating solvent at $320^{\circ}C$. The coordination modes and distinct thermal behaviors of the intermediate non-hydrated SbOl complexes are comparatively investigated by thermo-analytical techniques. When the reaction temperature is increased, the particle size is found to increase linearly. The crystallinity of the $CoSb_2$ nanoparticles prepared at $250^{\circ}C$ is amorphous phase without any peaks. $CoSb_2$ structural peaks start to appear at $300^{\circ}C$ and dominant peaks with high crystallinity are synthesized at $320^{\circ}C$. The potential chemical structures of non-hydrated SbOl and their reaction mechanisms by thermolysis are elucidated. The elemental composition and crystallographic structure of $CoSb_2$ nanoparticles suggest a bimodal interaction of the organic shell and the nanoparticle surface, with a chemical absorbed inner layer and physically absorbed outer layer of carboxylic acid.

• Journal of the Korean Ceramic Society
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• v.50 no.6
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• pp.476-479
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• 2013

$CoSb_3$ with its high electrical conductivity, Seebeck coefficient and rather low thermal conductivity is quite a promising material for thermoelectric conversion applications. A potentially high figure of merit (ZT) can be achieved by a nanostructure evolution of thermoelectric materials. In this work, $CoSb_3$ nanoparticles were synthesized through a thermal decomposition method in cooperation with a hot injection technique. Nano-sized $CoSb_3$ particles were obtained through the thermal decomposition reaction between the pre-heated cobalt-oleate at $320^{\circ}C$ and the injected antimony oleate with room temperature. The results showed that the particle size was increased with increasing synthesis temperature and the crystallinity of particles was improved with temperature but the decomposition of $CoSb_3$ was observed at $320^{\circ}C$. The $CoSb_3$ particles synthesized at $300^{\circ}C$ showed a high purity and an homogeneous shape with average particle size of 26 nm.