X-Ray Diffractograms of Cotton: Effect of Sample Weight and Other Variables

Abstract

Day-to-day and within-day variation in the principal peak height and in the area under the curve of x-ray diffractograms from a single specimen of cotton cellulose were examined. A normalizing procedure was shown to be capable of removing much of the short-term random variation in peak height. An appropriate standard sample weight for a 1 cm × 2 cm rectangular x-ray specimen of cotton cellulose is 100 mg. Samples of 50 mg give diffractograms of lower over-all intensity; however, the normalizing procedure makes peak heights from 50-mg samples compatible with similar data from 100-mg samples. Cement of the type and quantity described can be used to hold cotton fibers in a compact specimen without affecting the diffractogram. Steel supporting plates and steel specimen holders should be used with caution when irradiating with copper K α radiation, since undesirable background radiation can be produced by fluorescence of the iron in the steel. Aluminum holders are recommended.