Structural transition in thin vanadyl-phtalocyanine films deposited by Langmuir technology was studied in detail with the help of the vacuum adsorption and optical spectroscopy techniques. The reversible structural transition observed only in super-thin Langmuir films is accompanied by nonreversible changes during heating. This transformation of the film having defects and amorphous regions occurs during the film transition from a metastable state to a more stable one that is characterized by a lower free energy.
68.18.Jk Phase transitions in liquid thin films
$^1$Department of General Physics and Molecular Electronics, Faculty of Physics, Moscow State University, Moscow, 119991, Russia
$^2$Shubnikov Institute of Crystallography, Russian Academy of Sciences, Leninskii pr. 59, Moscow, 117333, Russia