[en] By the method of thermal decomposition of chelate organometallic compounds (OMC) ensuring the low-temperature (∼ 300 deg C) process of growth, epitaxial films of A²B⁶ compounds are prepared and their properties are studied. It is assumed that possible causes of appearance of metastable phases in condensates prepared by thermal decomposition of chelate OMC are bound with the non equilibrium of the process of epitaxial layer growth in case of OMC decomposition as well as with formation on substrate of metal - sulfur complexes in high energy electron-oscillating states at the transition of which into basic state during crystallization the energy leading to local heatings sufficient for phase transformation is released