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The purpose of our study is to determine the influence of elastic energy on the spinodal decomposition ranges of InAlGaN alloys lattice-matched to GaN. The distinction in lattice constants of the binary compounds constituting these alloys gives rise to their deformation energies. Such energies provide the tendency to disintegration that can lead to an appearance of the thermodynamically unstable states with respect to the decomposition. The initial stage of spinodal decomposition of the InAlGaN quaternary alloys is accompanied by transfers of atoms over distances of a lattice parameter. Accordingly, these transfers produce a thin two-layer region with negligibly small differences in their compositions. Formation of these layers causes the elastic energy. The alloys are represented as quaternary regular solutions. The internal deformation energy is calculated with the interaction parameters estimated by the valence force field model. The spinodal decomposition ranges of these materials are demonstrated up to 580 °C (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Self-assembling of 1O4Mg tetrahedral clusters in ZnTe-rich Mg x Zn 1 - x O y Te 1 - y alloys in the ultra dilute oxygen impurity limit from y = 1 × 10 - 8 to y = 1 × 10 - 3 is presented for the lower growth and higher annealing temperatures of 300 and 500 ∘ C , respectively. Under estimated conditions the free energies of the random alloys and alloys in which all impurity atoms are placed in the clusters are equal to each other. The advantage of the MgO and ZnTe bonding over the MgTe and ZnO one as well as a decrease of the strain energy after formation of 1O4Mg clusters are the origins of this phenomenon.

The spinodal decomposition ranges of low N-content B x Ga 1−x N y (P,As) 1−y /Ga(P,As) alloys grown on Ga(P,As) (001) substrates, are described. The alloys are represented as strictly regular solutions. In the analysis, we take into account the transformation of the bonds, strain and elastic energies. Spinodal decomposition ranges of B x Ga 1−x N y P 1−y alloys with compositions x = 0.01, 0.013, 0.015 and 0 ≤ y ≤ 0.08 are demonstrated up to 1100°C, and to B x Ga 1−x N y As 1−y with compositions x = 0.008, 0.01, 0.011, 0.012 and 0 ≤ y ≤ 0.06 are demonstrated up to 1180°C. The estimations show that the decomposition ranges are larger when the transformation of the bonds is not considered.

Spinodal decomposition of the GaSbxNyAs1-x-y quaternary alloys lattice-matched to the GaAs as the result of the internal deformation and coherency strain energies is described. The alloys are represented as quasiternary regular solutions. The internal deformation energy is presented by the interaction parameters between the constituent compounds estimated within the framework of the valence force field model. Ranges of spinodal decomposition of the GaSbxNyAs1-x-y alloys up to yles0.035 with and without coherency strain energy are demonstrated.