Debye Sherrer

To better understand the differences in their catalytic behavior, the catalysts were characterized by XRD and UV-vis DRS. Unfortunately, except for the peak at 77.6° 26 (311 diffraction), the other Au diffraction peaks overlapped with those of y-Al203. The size of the coherent domains of Au, listed in Table I, were estimated using the width of this diffraction peak and the Debye-Sherrer equation. They showed that catalysts of both groups A and C had small coherent domains, whereas those of group B had large domains. 

X-ray diffraction experiments were performed on a STOE STADI-P diffractometer (CuKai radiation X = 1.5406 A) equipped with a linear position-sensitive detector. The solutions and the solids were introduced in a 0.3mm capillary Lindemann tube (Debye-Sherrer geometry). 

DEBYE, PETER J. W. (1884-1966). A Dutch chemist and physicist who received the Nobel prize for chemistry in 1936 for his contributions to our knowledge of molecular structure through his investigations on dipole moments and on the diffraction of X-rays and electrons in gases. The interference patterns are still called Debye-Sherrer rings. He also made outstanding contributions to knowledge or polar molecules and to fundamental electrochemical theory. 

X-Ray diffraction powder patterns were developed by using a chromium source and a Phillips Debye-Sherrer camera. Due to their small size, the samples from the back of the halberd were irradiated for 12.5 h, and the green pseudomorph sample for 12.3 h. The black pseudomorph sample, larger, was irradiated for only 5 h. The exposed film was measured in accordance with standard procedures (8) and the resulting diffraction spacing values were compared to standard values of known materials (9). 

An exjjerimental device was built several years ago in which a beam of clusters is crossed by an electron beam. The resulting Debye-Sherrer diffraction rings are recorded on a photographic plate. A schematic view of the apparatus is shown in Fig. 1. The chosen compound in the vapor state, at inlet pressure pg and inlet temjjerature Tg, passes through a nozzle, 0.2 mm in diameter, and expands into vacuum in the form of a free jet. During this... 

The observed lattice parameter for the Pt-Ru/C sample follows from the presence of a solid solution of Pt and Ru. According to the variation of afcc with composition for Pt-Ru bulk alloys, an atomic fraction of 45% Ru should be present in the carbon supported alloy. An average particle size for the metal crystallites of 23 A and 20 A in the Pt/C and Pt/Ru/C catalysts, respectively, was determined from the broadening of the (220) diffraction peak by using the Debye-Sherrer equation. 

Debye-Sherrer method A method of recording X-ray diffraction patterns on film (i.e., Debye-Sherrer photographs). 

Figure 3.123 Size-dependent evolution of powder XRD patterns for CoPt3 nanoc stals. The average nanoc stal sizes were calculated using the Debye-Sherrer equation. Reproduced with permission from Ref [55] 2003, American Chemical Society.

It is considered that two diffraction peaks at /-spacings of 0.52 nm (100) and 0.23 nm (101) are attributed to the crystalline perfluorinated backbone of Nation 115. Others (0.44,0.365,0.264, and 0.170 nm) are assigned to ZrP crystal in the composite membrane, because these peaks matched up with the typical peaks of crystalline ZrP in literatures. " At the same time, these diffraction peaks also agreed well with the XRD pattern of ZrP powder. According to the Debye-Sherrer formula, the mean particle size of ZrP can be calculated to be about 5.0 nm from two peaks at 0.264 and 0.17 nm. The EDX pattern effectively verified the presence of ZrP. It was also found that the atomic ratio of P and Zr was 1.74, which is close to 2, the value in the molecular formula Zr(H2P04)2. 

Structural chemistry of solutions started in Japan rather late compared with other studies of solutions, although crystallographic investigations were very highly developed and actively investigated in Japan. This fact may be due to lack of the concept of structure of liquids in most Japanese physical chemists. The concept of "structure was soundly applied to solids and molecules in the gas phase, but not to liquids and solutions. X-Ray diffraction studies on liquids and amorphous substances were already examined in 1916 by Debye and Sherrer , immediately after the first work of Debye for the X-ray diffraction. Studies on liquid metals and molten salts by using X-... 

Roentgen, W. K. (1845-1923). A German physicist who discovered X rays in 1895, for which he was awarded the Nobel Prize in 1901. Application of these to a number of important problems in analytical chemistry was developed by the Braggs, Moseley, von Laue, and Debye and Sherrer. 

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