Determination of Particle Size of a Dispersed Phase by Small-Angle X-ray Scattering

1989 ◽  
Vol 171 ◽  
Author(s):  
Frank C. Wilson

ABSTRACTA method for determining particle diameters up to ca 500 rnm is described. X-ray data are obtained with an ultra-high resolution Bonse-Hart diffractometer and subsequently desmeared. The resultant data, viewed as the invariant argument h l(h), are interpreted as arising from a log-normal distribution of independent spherical particles. The distribution is characterized by its median value and breadth.

1992 ◽  
Vol 7 (7) ◽  
pp. 1856-1860 ◽  
Author(s):  
Manjula M. Ibrahim ◽  
Jianmin Zhao ◽  
Mohindar S. Seehra

In this paper, the techniques of SQUID magnetometry and line broadening in x-ray diffraction are employed for determining an important parameter for catalysts, viz. the particle size distribution. Magnetization versus temperature (5 K–400 K) and magnetization versus field (up to 55 kOe) data are reported for an α–Fe2O3 based catalyst. After determining the region of superparamagnetism, the distribution function f(r) is determined assuming a log normal distribution and Langevin paramagnetism of superparamagnetic particles. The distribution is found to be fairly symmetric with center near 65 Å and range of 35 to 115 Å. From line-broadening of Bragg peaks in x-ray diffraction, particle radii varying between 75 Å and 110 Å are obtained. These results are compared with the reported Mössbauer measurements of Huffman et al. on the same sample.


2008 ◽  
Vol 15 (6) ◽  
pp. 618-623 ◽  
Author(s):  
Hiroshi Fukui ◽  
Tomoo Katsura ◽  
Takahiro Kuribayashi ◽  
Takuya Matsuzaki ◽  
Akira Yoneda ◽  
...  

1968 ◽  
Vol 12 ◽  
pp. 87-96
Author(s):  
R. W. Gould ◽  
S. R. Bates

AbstractIt has been recently shown that particle size distributions can be determined from small angle x-ray scattering data. Size distributions have previously been measured in aluminum-zinc and aluminum-silver alloys containing spherical Guinier-Preston zones. Inorder to obtain the size distribution it is only necessary to calculate the Guinier radius and the Porod radius.Dispersion hardened nickel alloys containing small spherical particles of thoria appear to be amenable to this type of analysis. A nickel-20% chromium-2% ThO2 alloy was selected for this study. The particle size distribution obtained by small angle x-ray scattering is compared with the transmission electron microscopy results found in the literature.


Author(s):  
S. Rao ◽  
C. R. Houska

X-ray diffraction profiles and Fourier coefficients are given for particles distributed according to experimentally verified size distributions. Calculations are based upon the log normal distribution of sphere diameters and intercept lengths in addition to a normal distribution of column heights. It is found that the diffraction profile is not sensitive to the fine details of the distribution but rather the mean column height and the column-height variation coefficient. Errors in particle-size determinations will result from an improper choice of the variation coefficient. Two simplified models are given that describe the diffraction profiles for a large range of variation coefficients.


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