Powder X-ray diffraction analysis

The crystal structures of four chlorinated derivatives of di-benzo-p-dioxin have been determined by x-ray diffraction from diffractometer data (MoKa radiation). The compounds, their formulae, cell dimensions, space groups, the number of molecules per unit cell, the crystallographic B.-factors, and the number of observed reflections are given. The dioxin crystal structures were performed to provide absolute standards for assignment of isomeric structures and have been of considerable practical use in combination with x-ray powder diffraction analysis. 

In 1976, an X-ray powder diffraction analysis of a substance obtained from Te02, dissolved in concentrated hydrofluoric acid, was performed (96). The orthorhombic crystals had the composition H2Te203F4. The structure was shown to be characterized by... 

From a room temperature X-ray powder diffraction analysis LaeCo Sb was found to crystallize with the ordered La6ConGa3, i.e., the Nd6Fei3Si type structure, a = 0.8097, c = 2.3289 (Weitzer et al., 1993). An alloy was synthesized from ingots and compacted powders of the constituting elements (99.9% pure) by arc-melting, followed by annealing at 1073 for 5 days and quenched in cold water. 

From a room temperature X-ray powder diffraction analysis SnvT cnSb was found to crystallize with the ordered La6ConGa3, i.e., the NdfT c Si type, a = 0.8041, c = 2.3048... 

Ho-PtSb. An X-ray powder diffraction analysis oftheHoPtSb compound showed that it had the MgAgAs type structure with a = 0.6508 (Dwight, 1974). For the sample preparation, see ScNiSb. 

ASTM method D3175 (H), and forms of sulfur by ASTM method D2492 (21). Elemental analysis of the ash was performed using ASTM method D3682 (22). Carbon aromaticity was determined using 13c NMR CP-MAS procedures described elsewhere (13). X-ray powder diffraction analysis of the mineral matter in the whole coal was performed using a Rigaku powder dif-... 

Abstract. Gas interstitial fullerenes was produced by precipitation of C6o from the solution in 1,2 dichlorobenzene saturated by O2, N2, or Ar. The structure and chemical composition of the fullerenes was characterized by X-ray powder diffraction analysis, FTIR spectroscopy, thermal desorption mass spectrometry, differential scanning calorimetric and chemical analysis. The images of fullerene microcrystals were analyzed by SEM equipped with energy dispersive X-ray spectroscopy (EDS) attachment. Thermal desorption mass spectroscopy and EDS analysis confirmed the presence of Ar, N and O in C60 specimens. From the diffraction data it has been shown that fullerite with face centered cubic lattice was formed as a result of precipitation. The lattice parameter a was found to enhance for precipitated fullerene microcrystals (a = 14.19 -14.25 A) in comparison with that for pure C60 (a = 14.15 A) due to the occupation of octahedral interstices by nitrogen, oxygen or argon molecules. The phase transition temperature and enthalpy of transition for the precipitated fullerene microcrystals decreased in comparison with pure Cgo- Low temperature wet procedure described in the paper opens a new possibility to incorporate chemically active molecules like oxygen to the fullerene microcrystals. 

Fluorocarbonyl complexes of molybdenum(II) and tungsten(II) are much less common than their other halogen counterparts. However, several examples have been reported. For example, the selective fluorination of [Mo(CO)6] with XeF, in perfluoro solvents or HF yields [MoF2(CO)3], which has been characterized by 1R, mass spectrometry, and X-ray powder diffraction analysis.195... 

Protactinium metal reacts with hydrogen to form the black hydride, PaHj, which is isostructural with other actinide trihydrides it has only been prepared in submilligram amounts and identified by X-ray powder diffraction analysis (125). 

Area detectors record diffraction pattern in two dimensions simultaneously. Not counting the photographic film, two t)q)es of electronic area detectors have been advanced to a commercial status, and are becoming more frequently used in modem x-ray powder diffraction analysis. 

D. K. Smith, Particle statistics and whole pattern methods in quantitative X-ray powder diffraction analysis, Adv. X-Ray Anal., 1992, 35, 1-15. 

For more quantitative measurement. X-ray powder diffraction analysis is commonly used in industry (Hancock 1997 Jenkins 2000). A crystalline solid will typically show several distinct peaks which reflect the unique structure of crystals, whereas an amorphous solid will have no distinct peaks. This technique could be further used to assess quantitatively the degree of amorphism within a sohd, as mentioned in Example 12-5 (Connolly et al. 1996). In this case, it has been demonstrated that the shift of baseline of X-ray diffraction spectra is proportional to the degree of amorphism in the soUd phase (Crocker and McCauley 1995). 

In order to explain the structure of the LiF-B203 melts, the composition of the quenched samples was determined by means of X-ray powder diffraction analysis and IR spectroscopy. Both methods eliminated the presence of LiBp4 in the mixtures. On the other hand, the presence of LiB02 up to 5 mole % B2O3 and of 0126407 at higher... 

Z Ba(OH)2 These samples were then charged into the reactor under nitrogen, tested, removed from reactor under nitrogen and subject to X-ray powder diffraction analysis. The XPS and electron microscopic analyses were carried out on air-exposed samples. Similar analyses were carried out on untested catalysts. 

XRD (X-Ray powder Diffraction) analysis was performed with a Philips X PERT diffractometer equipped with a secondary monochromator data were collected in the 15<20<9O° angular region, with 0.03° 20 step and 20 s/step accumulation time the CuKa radiation (X=l.54178 A) was used. 

A X-ray powder diffraction analysis was performed on a Rigaku X-ray diffractometer... 

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