  In the present study we compare a structure of a Langmuir film assembled from
magnetic iron oxide nanoparticles on water surface and a structure of the same
film after its transfer to a solid substrate by the Langmuir-Schaefer method.
In contrast to most of related studies, where different techniques are used to
characterize the films before and after the deposition, we use the same
combination of X-ray reflectometry and Grazing Incidence Small-Angle X-ray
scattering. In both cases -- on a liquid and on a solid substrate -- the film
was identified as a well-ordered monolayer of the nanoparticles laterally
organized in a two-dimensional hexagonal lattice. However parameters of the
lattice were found to be slightly different depending on the type of the
substrate. It is also demonstrated that Langmuir-Schaefer technique is the
right way for deposition of such kind of the particles on a solid substrate.
