From Occupied Voids to Nanoprecipitates: Synthesis of Skutterudite Nanocomposites in situ

摘要: Nanocomposite thermoelectrics can exhibit both reduced thermal conductivity and enhanced electrical beyond single-phase materials; accordingly, they have become the new material paradigm to achieve viable thermoelectric efficiencies. New synthesis techniques are needed further enhance their properties. A novel technique, designed synthesize nanoprecipitates within a well-sintered polycrystalline matrix, is reported. The attrition-enhanced nanocomposite (AENS), comprises three stages: (1) Synthesis of cage-like crystal structures with metastable interstitials, followed by (2) severe plastic deformation (SPD), finally (3) rapid sintering concomitant interstitial precipitation. efficacy this technique demonstrated in work. Filled skutterudite In0.2Co4Sb12 samples synthesized spark-plasma sintered. They subjected via high-pressure torsion, sintered again order precipitate interstitials. X-ray diffraction, scanning-electron microscopy, small-angle neutron scattering (SANS) procedure demonstrate that indium precipitates rapidly, forms nano-sized In-based inclusions. In addition, amount precipitated indium, size distribution strongly influenced extent deformation. This be employed efficient as well materials number applications requiring precipitates.