Vanadium powder pattern

This compound has two crystallographically distinct vanadium sites. While the static spectrum is a superposition of two powder patterns of the kind shown in Figure 3, MAS leads to well-resolved sharp resonances. Weak peaks denoted by asterisks are spinning sidebands due to the quadrupolar interaction. 

The XRD powder patterns of V-containing silicalite samples indicate in all cases the presence of only a pentasyl-type framework structure with monoclinic lattice symmetry, characteristic of silicalite-1 no evidence was found for the presence of vanadium oxide crystallites. The analysis of cell parameters of VSU545 does not indicate significant modifications with respect to those found for pure silicalite-1. This is in agreement with that expected on the basis of the small amount of V atoms present in V-containing silicalite. 

The valence state of vanadium in the catalyst was determined by chemical analysis, as described previously [7]. Fourier-transform (FT-IR) infrared spectra were recorded with a Perkin Elmer 1750 instrument in a quartz cell connected to grease-free evacuation and gas manipulation lines. The self-supporting disk technique was used. X-ray diffraction (XRD) patterns were recorded with a Perkin Elmer 1050/81 diffractometer using the powder technique and CuKg radiation. 

The X-ray powder diffraction pattern of vinblastine sulfate has been reported by Beer et al.0 using vanadium-filtered chromium radiation and a wavelength value of 2.2896 t in the calculations ... 

In-situ neutron diffraction was used to monitor the structural evolution of the phase decomposition of MAX phases at high-temperature in real time. Diffraction patterns were collected using WOMB AX at OPAL or the Polaris at ISIS, both are high-intensity medium-resolution powder diffractometers. Samples were mounted in a high-temperature niobium furnace which was fitted with a thin tantalum foil element and tantalum and vanadium heat shields that allows it to reach 2000°C, and operates under a high dynamic, i.e., it is continuously evacuated with a vacuum of 10 - 10 torr. A precision electronic scale was used to weigh the sample before it was loaded into the furnace. 

Deuterated af-PS (af-dPS) of Af = 239,000 and = 338,000 was synthesized, and characterized by gel permeation chromatography. It was dissolved in cyclohexane, precipitated in the form of a powder in methanol, and dried at 90 C. The resulting powder was loaded into a 1/4 inch diameter cylindrical vanadium cell. Vanadium was chosen in order to avoid an overlap between the diffraction pattern of the sample and that of the container. A series of WANS experiments were performed on the 2XD powder diffractometer at the Missouri University Research Reactor. 

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