XRD spectrum

FIGURE 2.9 X-ray diffractogram (XRD) spectra of unmodified and modified nanoclays and styrene-butadiene rubber (SBR)-based nanocomposites with styrene content of (a) 15% and 40% and (b) 23%. (From Sadhu, S. and Bhowmick, A.K., J. Polym. Set, Part B Polym. Phys., 42, 1573, 2(304. Courtesy of Wiley InterScience.)... 

Fig.2 XRD spectra of LiNiLaOx catalysts with different Li content...

In situ XRD spectra were collected on beam line X18A at the National Synchrotron Light Source (NSLS) located at Brookhaven National Laboratory (BNL). The X-ray wavelength (X) was 1.195 A. The step size of the 29 scan was 0.02° in the regions with Bragg reflections and 0.05° in the regions without reflections. The XRD spectra were collected in the transmission mode (Liu et al., 2004). 

The growth of crystalline nanoparticles was also visible with powder X-ray diffraction of dried Ti-Beta gels. XRD spectra show that after 28 hours of synthesis procedure Ti-Beta crystals grow to a sufficient size to be detected. In samples that were hydrothemally treated less than 28 hours, no peaks in XRD patterns were observed. After 48 hours of synthesis the sample was already fully crystallized and had the distinguishable Ti-Beta XRD pattern (Figure 3). 

Figure 1. XRD spectra of the intermediate phase (sample 5) and disordered cancrinite (sample 6)...

Figure 1(a) compares the XRD spectra of both Beta sample the conventional one and that prepared from organofunctionalized seeds, showing their high crystallinity. However, for the sample prepared using the seed silanization treatment, the peaks are less intense and broader compared to those corresponding to the conventional zeolite, suggesting that the Beta (PHAPTMS) presents smaller crystalline domains. 

The XRD spectra for the nonvolatile material produced from the pyrolysis of 7, with the Joint Committee on Powder Diffraction Standards (JCPDS) reference patterns for CuInS2 (27-0159), confirmed it to be single-phase CuInS2 (see Fig. 6.9). Examination of the EDS spectra for the same samples shows predominant emissions from Cu, In, and S edges, with the approximate percentage atomic composition of 27, 23, and 50 for 7 and 28, 23, and 49 for 8, respectively, thus supporting the formation of CuInS2. 

Figure 6.19. XRD spectra highlighting the 220/204 reflections of a CuGaS2 film (bottom Ts = 450 °C), a CuInS2 film (top Ts = 400 °C) and alloy films having InxGay contents in the range In0 27Ga0 73—In0 43Ga0 57. All films were deposited on fused silica.

Figure 6.22. XRD spectra of CuInS2 films grown by AACVD (a) untreated films, (b) film III with postdeposition annealing, and (c) GAXRD spectrum of film IV.

Figure 6.20 Quick EXAFS and XRD measurements recorded during the temperature programmed reduction of copper in a Cu/Zn0/Al203 methanol synthesis catalyst. The disappearance and appearance of peaks with increasing temperature in the series of EXAFS spectra corresponds to the conversion of oxidic to metallic copper. The intensity of the relatively sharp peak around 9040 eV, indicative of Cu metal, clearly illustrates the kinetics of the reduction process, as does the intensity of the (111) reflection of Cu metal in the XRD spectra (adapted from Clausen 44J).

Figure 6.20 shows an example in which QEXAFS has been used in combination with XRD to study the temperature programmed reduction of copper oxide in a Cu/ZnO/Al203 catalyst for the synthesis of methanol [43,44]. Reduction to copper metal takes place in a narrow temperature window of 430-440 K, and is clearly revealed by both the EXAFS pattern and the appearance of the (111) reflection of metallic copper in the XRD spectra. Note that the QEXAFS detects the metallic copper at a slightly lower temperature than the XRD does, indicating that the first copper metal particles that form are too small to be detected by XRD, which requires a certain extent of long range order [43,44],... 

XRD spectra were compared to JCPDS file Calculated using Scherrer equation (King and Alexander, 1974). 

Figure 3.37. XRD spectra of (a) tetragonal a-cristobalite and (b) chemically stabilized cristobalite (CSC, CaO 2Al2O3 40SiO2 or 1 2 40 composition) at room temperature with Ca and A1 dopants, which exhibits the structure of the high-temperature 0-phase.

Fig. 3.2 XRD spectra showing the process of PbSe formation from the reaction of precipitated hydrated lead oxide with Na2SeS03 solution, (a) Starting material (b-e) after 1.5, 3, 4.5, and 6 mn reaction, respectively. (Adapted from Ref. 46.)... 

In the tables for both Cu-S and Cu-Se (Tables 6.4 and 6.5), the column denoting conductivity type has been deleted (these semiconductors are always p-type), and, in its place, the phase (and/or composition) has been given. In some cases, particularly for the sulphides, where no XRD pattern was seen (except for CuS), no phase (or composition) was proven and therefore no entry is given in the table. This was not a problem for Cu-Se, since XRD spectra were always clear and definitive. 

The films (both ZnO and ZnO Al) were wurizite stracture with a preferential texturing (c-axis -L substrate). No AI2O3 was found in the XRD spectra, suggesting either dispersal of the A1 in the ZnO matrix or its presence as very tiny crystals of (hydr)oxide on the ZnO surface. TEM measurements showed an average grain size of 25 nm (ZnO) and 45 nm (ZnO Al). 

Fig. 27 XRD spectra of S-SBR reinforced with OMMT. Note that the spectra of the related clays and organoclays are also shown. The position of the (001), (002), and (003) reflexes are indicated...

Hydrolysis of Alkoxides - A different thermal evolution of the precursor phase was observed for a BaAli20i9 sample prepared via hydrolysis of alkoxides.8,9 For this sample no XRD diffraction lines were detected after heating at 1000°C. At 1200°C Ba-hexaaluminate formed, and it was the only phase detected in the XRD spectra. Calcination at 1450 °C resulted in higher sharpness and intensity of the XRD reflection of Ba-hexaaluminate. No further changes were observed upon calcination at 1600°C. Also in this case, the appearance of Ba-(3-Al203 was accompanied by a marked drop of surface area. However, the... 

The phase composition of catalysts was studied by X-ray diffraction [XRO) technique. XRD spectra were recorded by using a Phillips 17D0 powder diffractometer equipped with a graphite crystal monochromator and CuK radiation. 

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