Self-organization processes in impurity subsystem of solid solutions Original Research Article

New experimental results proving the existence of critical phenomena in the range of small impurity concentrations (∼1.0 at.%) in a number of ternary solid solutions based on IV–VI semiconducting compounds are presented. An anomalous decrease in X-ray diffraction linewidth and an increase in the lattice thermal conductivity and heat capacity in this concentration range were observed. The experimental results are analyzed on the basis of percolation theory and fluctuation theory of the second order phase transitions. From the experimental data, the critical exponents for the lattice thermal conductivity and lattice heat capacity are determined. It is suggested that self-organization processes (a short-range or long-range ordering of impurity atoms) accompany the percolation phenomena. The results obtained in this work represent another evidence to the proposition about the universal character of critical phenomena accompanying the transition from an impurity discontinuum to an impurity continuum.