Radiation-chemical decomposition of heavy metal azides - II. Silver azide radiolysis scheme

As a result of complex studies on the nature and properties of final products and intermediate particles using a wide number of experimental topography and radiolysis kinetics methods, we offer the AgN3 radiolysis scheme including the following stages: homogeneous excitation of electron subsystem with 'hot' electrons and holes formed; 'hot' electron and hole thermalization with possible formation of N4- radical in volume on the point defects; electron localization on the immobile structural defects whose neighbourhood is rich in the mobile positively charged point defects; metal particle formation due to electrostatic attraction of the nearby mobile defect to the localized electron, with no thermal excitation; metal particle growth, according to both the diffusional mechanism of delivering the volume of corresponding positively charged point defect with consequent electron capture, and by decomposing anions on the interphase with the consequent border layer cation addition to the growing metal particle, interior space formation in the volume by disintegrating 'hot' excitons into ion defect pairs; nitrogen formation on the exterior and interior surfaces, as well as those formed by radiation, either by trapping the hole by surface cation vacancy or by removing the surface cation of the hole with the consequent addition of the second hole to the Vsub(F)-center, and by disintegrating the activated complex into three nitrogen molecules. For the above stages the characteristic parameters are determined by means of direct measurement and calculation. The kinetics and energy conditions of the process are also found. (author)