X-ray reflectivity prove of Langmuir–Blodgett superlattice formation of lead and yttrium stearate alternative bilayers

Multilayer Langmuir–Blodgett (LB) films with X-ray contrast in between the neighbouring bilayers is proposed as an object for the investigation of the interlayer diffusion. Yttrium and lead stearates are chosen to form such kind of films. A double-section LB trough was used for deposition. X-ray reflectivity measurements are used to examine the formatted LB films. X-ray reflectivity data have verified that highly ordered LB films with alternating of yttrium stearate and lead stearate bilayers are obtained. Sharp Bragg peaks occur up to 11th order. Size of the corresponding one-dimensional elementary unit cell is about 100 Å (yttrium stearate bilayer+lead stearate bilayer). A system of well-defined Kiessig fringes between the Bragg peaks is also observed. From the positions of the Kiessig fringes, the thickness of the films (from 200 to 1000 Å) was calculated. These values absolutely correspond to the number of the deposition cycles multiplied on the monolayer thickness.