Structure studies of langmuir‐blodgett films

A method of small‐angle X‐ray investigation of the structure of Langmuir‐Blodgett (L‐B) films on substrates is developed. Experiments were carried out using a small‐angle X‐ray diffractometer with a position‐sensitive detector. X‐ray patterns contain 10–15 reflections with spacings from 50 Å up to 250 A and a number of ripples in the inner parts of the curves. An analysis of these ripples revealed integral parameters of L‐B films (thickness 100 ‐ 2000 A, a number of monolayers: 1–50). The Fourier‐synthesis of the structural amplitudes gave electron density profiles across the films. These profiles demonstrated the successive realization of pre‐programmed sequences of alternating bilayers in L‐B superlattices.