X-Ray Diffraction Data on Evaporated Organic Films of Fatty Acids

Abstract

It was found by X-ray analysis and mass-spectrography that organic films of margaric and palmitic acids, belonging to a group of long chain saturated fatty acids, were obtained by thermal evaporation in vacuum. The present paper deals with their structural analysis by the powder diffraction X-ray technique: They are characterised by the fact that they posess a preferred orientation of the monoclinic structure with the basal plane which is parallel to the substrate plane, and that they show no thermal decomposition of the powders. In addition, the X-ray diffraction data on powder margaric acid is presented which exhibit several more peaks, not reported in an earlier work. The Miller indices are also assigned to the initial several peaks in the case of margaric acid. Alternation in physical properties expected between odd and even members of the fatty acids could not be found between margaric and palmitic acids as far as the crystal structure of the films is concerned.