The Segregation Charge Transfer (SCT) model, already applied to binary metallic alloys, is adapted to interpret the nucleation either of crystalline, or of vitreous phases in binary non-metallic compounds ion bombarded under con-ditions favourable to the formation of dense collision cascades. At the cascade-matrix interface a non-equilibrium electronic density profile develops; it is re-equilibrated by charge transfer reactions (CTRs), each involving a couple of dissimilar atoms, which are ionized. The sum of the volumes of such ionized atoms and of neutral atoms which exceed the stoichiometry ratio needed by the reaction, is compared to the volume occupied in the starting compound unit cell by a prototypical stoichiometric unit. The local deformation associated to the local volume changes can be high enough to structurally destabilize the surrounding crystal. The absolute value of the relative volume variation due to a CTR has been evaluated for 26 systems. A threshold value of such a structure stability parameter, allowing us to separate crystalline from amorphized compounds has been found. direct c 1999 Elsevier Science B.V. All rights reserved.
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