Synthesis Optimization and Thermoelectric Properties of S-Filled and Te-Se Double-Substituted Skutterudite under High Pressure.

In recent years, skutterudite filled with electronegative elements (S, Se, Cl, Br) has attracted the extensive attention of researchers. By doping electron donors (Pb, Ni, or Te, S, Se) at the Co or Sb sites, the electronegative elements can form thermodynamically stable compounds in the intrinsic pores of the skutterudite, substantially expanding the research scope of skutterudite. In this study, S0.05Co4Sb11.3Te0.6Se0.1 skutterudite was synthesized at high pressure and high temperature, with a pressure range of 2.0-3.5 GPa. The phase composition, micro-morphology, and electrical and thermal transport properties were systematically characterized. The micromorphology analysis shows that the introduction of S element and substituting Te and Se at the Sb sites inhibit the grain growth in a suitable high-pressure environment. Substantial differences are observed in the directions of the lattice stripes in the samples, and rich grain boundaries and many lattice distortions and dislocation defects occur. The carrier concentration can be optimized by filling the voids of the skutterudite with a few S atoms, and the thermoelectric properties can be optimized by scattering phonons through resonance scattering and defect scattering. The samples synthesized at a pressure of 3.0 GPa and a temperature of 900 K have a maximum power factor of 23.85 × 10-4 W m-1 K-2 and a maximum zT value of 1.30 at a test temperature of 773 K.

Optical high-precision three-dimensional vision-based quality control of manufactured parts by use of synthetic images and knowledge for image-data evaluation and interpretation.

Vision-based evaluation of industrial workpieces can make efficient use of knowledge-based approaches, in particular for quality control, inspection, and accurate-measurement tasks. A possible approach is to compare real images with conceptual (synthetic) images generated by use of standard computer-aided design models, which include tolerances and take the application-specific conditions into account (e.g., the measured-calibration data). Integrated in (industrial) real-life environments, our evaluation methods have been successfully applied to on-line inspection of manufactured parts including sculptured surfaces, using structured light techniques for the reconstruction of three-dimensional shapes. Accuracies in the range 15-50 microm are routinely achieved by use of either isolated images or spatially registered image sequences.