The Influence of Crystallite Size on the Apparent Basal Spacings of Kaolinite

Volkmar Trunz
Mineralogisch-Kristallographisches Institut der Technischen Universität, 3392 Clausthal-Zellerfeld, Säigemüllerstr. 4 West Germany

Abstract: For very small crystallites diffraction theory shows not only broadening of powder lines, but generally also a shift of the line position, depending on the change of the structure factor over the range of broadening. For decreasing thickness of kaolinite crystals (less than 50 layers) an increasing shift of reflections is found: the lines (001), (002), (004) and (006) are shifted to apparently larger spacings, the lines (003) and (005) to smaller spacings, resulting in a nonintegral series. Presuming a known crystallite size, tables are given for evaluating true spacings from measured values of 2θ.

Clays and Clay Minerals; April 1976 v. 24; no. 2; p. 84-87; DOI: 10.1346/CCMN.1976.0240206
© 1976, The Clay Minerals Society
Clay Minerals Society (www.clays.org)