Spinodal decomposition and composition modulation effect at the low-temperature synthesis of Ax3B1-x

Resonance of mixing energy and energy of elastic deformations during spinodal decomposition and the composition modulation effect in ZnхCd1-ХTe solid solutions

“…In [11], the fundamental equations for a spinodal decomposition of Cahn and Hilliard [5][6] were adapted to describe spinodal phase transformations occurring in the decay of a GaxIn1-xP semiconductor solid solution grown on a GaAs substrate. In the present work, this approach is extended to describe the process of spinodal decomposition of ZnxCd1-xTe solid solution when its layers or polycrystallites undergo spinodal decomposition in the absence of external stabilizing action of the substrate.…”

“…To derive the equation for the kinetics of spinodal decomposition, we start from the balance law for the concentration c written in the classical form G correspond to excess molar energy of solid phase mixture and excess phase energy of the deformed crystal (the expressions for them are given in [11]), the last term describes the dependence of W on the gradient of composition,  is the coefficient of power series for the free energy corresponding to the solid solution which is heterogeneous over its composition [5][6][7]11]. Since we are interested in the steady processes, the above equation…”

“…, where the parameter  coincides with the chemical potential of the solid phase [5][6][7]11]and is related to the mass conservation law [7]. Thus, the final expression for the spinodal decomposition equation reads as follows:…”

“…It was this that created the possibility of the appearance of an oscillatory process associated with the transition of the energy of a decaying solid phase into the elastic energy of deformed inclusions. Such a scheme of spinodal decomposition of the material was analyzed by us in [11] as applied to the description of the composition modulation effect in a solid solution forming a GахIn1-хР -GaАs heterostructure.…”

“…In such a situation, the inclusion of a new solid phase that appears due to the decomposition process differs in the CLP from the average CLP of the main matrix of the solid solution. This leads to a different method for calculating the values of elastic strains in the system, in comparison with the technique used in [11] when the elastic state of the film was controlled by the crystallographic parameters of the massive substrate. Indeed, in the case of the formation of an elastically deformed inclusion in the crystalline matrix of the material, its excess elastic energy must be calculated concerning the CLP of the initial material itself.…”