A precise determination of the shape, size and distribution of size of crystallites in zinc oxide by X-ray line-broadening analysis

1983 ◽  
Vol 16 (2) ◽  
pp. 183-191 ◽  
Author(s):  
D. Louër ◽  
J. P. Auffrédic ◽  
J. I. Langford ◽  
D. Ciosmak ◽  
J. C. Niepce

The Fourier and variance methods are used to analyse the breadths of X-ray diffraction peaks from ZnO powder obtained from the thermal decomposition of Zn3(OH)4(NO3)2. The shape, size, distribution of size and orientation of the crystallites are determined. It is found that the form is markedly anisotropic and that on average the crystallites may be regarded as cylinders with a diameter of about 110 Å and height about 240 Å, but that they are in fact right prisms whose cross section is an irregular hexagon. There is excellent agreement between the experimental results and the predictions of line-broadening theory, with quantitative confirmation from electron micrographs of the sample.

1997 ◽  
Vol 30 (4) ◽  
pp. 427-430 ◽  
Author(s):  
F. Sánchez-Bajo ◽  
F. L. Cumbrera

A modified application of the variance method, using the pseudo-Voigt function as a good approximation to the X-ray diffraction profiles, is proposed in order to obtain microstructural quantities such as the mean crystallite size and root-mean-square (r.m.s.) strain. Whereas the variance method in its original form is applicable only to well separated reflections, this technique can be employed in the cases where there is line-profile overlap. Determination of the mean crystallite size and r.m.s. strain for several crystallographic directions in a nanocrystalline cubic sample of 9-YSZ (yttria-stabilized zirconia) has been performed by means of this procedure.


2006 ◽  
Vol 118 ◽  
pp. 53-58
Author(s):  
Elisabeth Meijer ◽  
Nicholas Armstrong ◽  
Wing Yiu Yeung

This study is to investigate the crystallite development in nanostructured aluminium using x-ray line broadening analysis. Nanostructured aluminium was produced by equal channel angular extrusion at room temperature to a total deformation strain of ~17. Samples of the extruded metal were then heat treated at temperatures up to 300oC. High order diffraction peaks were obtained using Mo radiation and the integral breadth was determined. It was found that as the annealing temperature increased, the integral breadth of the peak reflections decreased. By establishing the modified Williamson-Hall plots (integral breadth vs contract factor) after instrumental correction, it was determined that the crystallite size of the metal was maintained ~80 nm at 100oC. As the annealing temperature increased to 200oC, the crystallite size increased to ~118 nm. With increasing annealing temperature, the hardness of the metal decreased from ~60 HV to ~45 HV.


1989 ◽  
Vol 33 ◽  
pp. 145-151
Author(s):  
M. O. Eatough ◽  
D. S. Ginley ◽  
B. Morosin

AbstractSuperconducting thin films (0.3-0.7μm) in the TI-Ca-Ba-Cu-0 system have been prepared on various single crystal substrates by sequential electron beam evaporation followed by appropriate sintering and annealing. Oxygen-annealed films show Tc as high as 110K and critical current densities to 600,000 A/cm2. X-ray diffraction analyses of these films show predominantly the Tl2Ca2Ba2Cu2O10 phase (c-parameter near 36Å), but some also contain up to 50 at% of the Tl2CaBa2Cu2O8 phase (c-parameter near 30Å). The complete absence of hkl reflections other than 00I demonstrates the highly oriented nature of the films as well as the absence of other Tl phases. The diffraction peaks are noticeably broader for the 36Å phase than for the 30Å phase. For a 0.7μm film such broadening is consistent with coherent sizes along the c-axis of 1200 - 1400Å and 500Å, respectively, for the 30Å and 36Å phases, and of strain values near 1.4-1.8 x 10-3 for both phases.


1991 ◽  
Vol 6 (4) ◽  
pp. 200-203 ◽  
Author(s):  
D. Rafaja ◽  
V. Valvoda

AbstractA method for the correction of peak position for the Seemann-Bohlin X-ray diffractometer, useful for practical application, is presented. The position of diffraction peaks is largely influenced by both the displacement of specimen from the diffractometer circle and the shift of the X-ray tube focus. The described correction method has been used for investigation of thin layers, especially for the precise determination of both lattice parameter and stresses in thin films. The application of the method is illustrated on samples of TiN and ZrN coatings deposited on steel substrates and additionally covered with a thin film of Si or Ta or TaC powder used as an internal standard.


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