*Institute of Mathematics and Mechanics of Russian Academy of Sciences, Urals Division,

Summary In the present work the mechanical properties of mercury semiconductors in the vicinity of the phase transitions were studied. Under the high hydrostatic pressure treatment the macroscopic bending of samples was observed, that gave the evidence of high plasticity of these materials near the phase transition point. The influences of chemical substitutions in cation and anion sublattices on the properties of ternary chalcogenides were analysed