X-RAY-DIFFRACTION STRUCTURAL-ANALYSIS OF LANGMUIR-BLODGETT-FILMS USING A PATTERN-RECOGNITION APPROACH

A new approach for the analysis of X-ray diffraction patterns to obtai n the structure of Langmuir-Blodgett (LB) films is reported. In partic ular, to solve the ''phase problem'' we apply a direct method, essenti ally a pattern recognition approach, which was recently proposed to de termine without assumptions the structure of liquid-crystalline phases , This approach is used to analyse two different types of samples, nam ely LB films of fatty acid salts and of bipolar lipids extracted from thermoacidophilic archaeon Sulfolobus solfataricus. As a result, the e lectron density profiles allow us to fully characterize the molecular arrangement in both the investigated films.