The Ce-Ni-Si System Revisited: More Homologue Compounds?

The nickel-rich region of the system Ce-Ni-Si has been reinvestigated utilizing X-ray single-crystal, powder, and electron diffraction as well as electron microprobe and thermal analyses. Two novel hexagonal compounds, τ-CeNiSi and τ'-CeNiSi were identified. The crystal structure of τ-CeNiSi was derived from single-crystal X-ray diffraction and found to be isotypic with the SmNiP-type structure (S.

Study of thermal stability of p-type skutterudites DDFeCoSb by Knudsen effusion mass spectrometry.

The temperature and phase stability of p-type skutterudites, DDFeCoSb, manufactured various preparation techniques, all exhibiting a high -level, have been studied by means of thermal analysis and Knudsen effusion mass spectrometry. The results from phase transformation measurements and characteristics of the evaporation of antimony, as the volatile element, supported by microstructure observations and by diffusion profiles are summarized and discussed in view of a full understanding of the degradation processes and knowledge of the long term operation stability of the bulk and nano-structured thermoelectrics studied. It was found out that the antimony evaporation is a complex diffusion kinetic process resulting in a stable Sb level dependent on the preparation route.

BaAl4 derivative phases in the sections {La,Ce}Ni2Si2-{La,Ce}Zn2Si2: phase relations, crystal structures and physical properties.

Phase relations and crystal structures have been evaluated within the sections LaNi2Si2-LaZn2Si2 and CeNi2Si2-CeZn2Si2 at 800 °C using electron microprobe analysis and X-ray powder and single crystal structure analyses. Although the systems La-Zn-Si and Ce-Zn-Si at 800 °C do not reveal compounds such as "LaZn2Si2" or "CeZn2Si2", solid solutions {La,Ce}(Ni1-xZnx)2Si2 exist with the Ni/Zn substitution starting from {La,Ce}Ni2Si2 (ThCr2Si2-type; I4/mmm) up to x = 0.18 for Ce(Ni1-xZnx)2Si2 and x = 0.

Changes in microstructure and physical properties of skutterudites after severe plastic deformation.

The best p-type skutterudites with ZT > 1.1 so far are didymium (DD) filled, Fe/Co substituted, Sb-based skutterudites. DD0.

Influence of Sn-substitution on the thermoelectric properties of the clathrate type-I, Ba8Zn(x)Ge(46-x-y)Sn(y).

A systematic investigation is presented on the influence of Sn-substitution in the clathrate-I compound Ba(8)Zn(x)Ge(46-x-y)Sn(y), particularly for the crystal structure and thermoelectric properties including electrical resistivity, Seebeck coefficient, and thermal conductivity. Two series of samples were prepared to explore the changes for different Sn-contents, (y), and to define the optimum Zn-content, (x), for Ba(8)Zn(x)Ge(46-x-y)Sn(y). Sn-incorporation leads to a linear expansion of the unit cell parameters.

Crystal structure of novel Ni-Zn borides: first observation of a boron-metal nested cage unit: B20Ni6.

The crystal structures of three ternary Ni-Zn borides have been elucidated by means of X-ray single-crystal diffraction (XSC) and X-ray powder diffraction techniques (XPD) in combination with electron microprobe analyses (EMPA) defining the Ni/Zn ratio. Ni(21)Zn(2)B(24) crystallizes in a unique structure type (space group I4/mmm; a = 0.72103(1) nm and c = 1.