[en] Nonaniobium phosphorus pentacosaoxide, PNb₉O₂₅, M_r=1267.11, tetragonal, I4/m, a=15.639 (2), c=3.8317 (4) A, V=937.1 (3) A³, Z=2, D_x=4.49 Mg m^-2, λ(MoKα)=0.71073 A, μ(MoKα)=5.27 mm^-1, F(000)=584, T=294 K, 316 reflections with I>3σ(I), R=0.033, wR=0.031. The framework is composed of ReO₃-type 3x3x∞ columns. Each column shares edges with the four neighboring columns and corners with the PO₄ tetrahedra. (orig.)

[en] Nine new phosphate bronzoides - ANb₂TiP₃O₁₅, ATa₂TiP₃O₁₅ and ANbSbTiP₃O₁₅ (A = K, Rb, TI) - and one new phosphate bronze RbNb₃P₃O₁₅ have been synthesized. The cell parameters of these phases have been determined and the crystal structure of RbNb₃P₃O₁₅ has been established from a single crystal X ray diffraction study. They are all isotypic with the niobium phosphate bronze KNb₃P₃O₁₅ whose structure is closely related to that of the tetragonal tungsten bronze (TTB). The structural evolution in the series is discussed

[en] Series of Fe thin films have been prepared by thermal evaporation onto glass and Si(1 0 0) substrates. The Rutherford backscattering (RBS), X-ray diffraction (XRD), Scanning electron microscopy (SEM) and the four point probe techniques have been used to investigate the structural and electrical properties of these Fe thin films as a function of the substrate, the Fe thickness t in the 76-431 nm range and the deposition rate. The Fe/Si samples have a <1 1 0> for all thicknesses, whereas the Fe/glass grows with a strong <1 0 0> texture; as t increases (>100 nm), the preferred orientation changes to <1 1 0>. The compressive stress in Fe/Si remains constant over the whole thickness range and is greater than the one in Fe/glass which is relieved when t > 100 nm. The grain size D values are between 9.2 and 30 nm. The Fe/glass films are more electrically resistive than the Fe/Si(1 0 0) ones. Diffusion at the grain boundary seems to be the predominant factor in the electrical resistivity ρ values with the reflection coefficient R greater in Fe/glass than in Fe/Si. For the same thickness (100 nm), the decrease of the deposition rate from 4.3 to 0.3 A/s did not affect the texture and the reflection coefficient R but led to an increase in D and a decrease in the strain and in ρ for both Fe/glass and Fe/Si systems. On the other hand, keeping the same deposition rate (0.3 A/s) and increasing the thickness t from 76 to 100 nm induced different changes in the two systems.

[en] Tripotassium 21-oxooctaniobate, M_r=1196.53, hexagonal, P6₃/mcm, a=9.1584(5), c=12.0404(4) A, V=874.6(1) A³, Z=2, D_x=4.54 Mg m^-3, λ(Mo Kα)=0.71073 A, μ=5.65 mm^-1, F(000)=1106, T=294 K, R=0.044, wR=0.047 for 2540 reflections with I>3σ(I). The framework is built up from [Nb₆O₂₄] units stacked along c giving [Nb₆O₂₁]_∞ chains which are held together by single NbO₆ octahedra. (orig.)