The (Ag,Pd)22Se6 phase was synthesized from individual elements by silica glass tube technique and structurally characterized from powder X-ray diffraction data. The (Ag,Pd)22Se6 phase crystallizes in Fm$\overline3$m symmetry, unit-cell parameters: a = 12.3169(2) Å, V = 1862.55(5) Å3, Z = 4, and Dc = 10.01 g/cm3. The crystal structure of the (Ag,Pd)22Se6 phase represents a stuffed 3a.3a.3a superstructure of the Pd structure (fcc), where only 4 from 108 available octahedral holes are occupied. Its crystal structure is related to the Cr23C6 structure type.

Phase diagrams and X-ray powder diffraction patterns provide critical information for thermoelectric (TE) research. We have conducted a survey of phase diagrams and powder diffraction patterns of TE systems in the ASM (American Society for Metals) Metal/Alloy database and ICDD (International Centre for Diffraction Data) PDF (Powder Diffraction File), respectively, for their availability and crystal systems. In this report, we focus on TE materials that have the half-Heusler XYZ structure, and related compounds, based on a set of materials selection rules. We found that among 306 potential XYZ compounds that we have surveyed, 234 have powder diffraction patterns in the PDF, but only 28 have phase diagram information, and 67 do not have any crystallographic information. Among the 234 phases with powder patterns, 84 were reported to have cubic F43m half-Heusler type structure, and the remainder have hexagonal, orthorhombic or other structure types. Some XYZ compounds have both cubic and hexagonal phases. This information will provide the basis for future activities for the improvement of the databases. These activities include filling the missing gaps in both phase equilibria database and the PDF, as well as adding TE and pertinent physical properties to the PDF.

Development of a versatile technique for fabricating ceramic thin films on plastics has long been a challenge for those who aim at providing the surface of lightweight, flexible plastics a variety of functions. Wet processing techniques that have been reported so far on the fabrication of ceramic thin films on plastics are reviewed in this article. The techniques include crystalline nanoparticle deposition, liquid phase deposition, sol-gel method and chemical solution deposition (CSD). In these techniques, the issue of how to crystallize and/or densify the films on plastic substrates without firing has been focused on, and it would be recognized that great efforts have been made on this issue. Self-combustion of CSD thin films is also introduced, which only requires heat treatment at low temperatures for films to be crystallized. Finally a transfer process that our group has proposed recently is presented, which is unique in that the crystallization and densification are guaranteed by a firing step.