Thermochemistry and reactivity of the azides - III. Thermal decomposition of silver azide and its sensitization by artificial lattice defects

Abstract

The kinetics of the thermal decomposition of silver azide have been studied and the results found to fit a rate equation d(N 2 )/d t = k (AgN 3 ) 2/3 . The energy of activation of the decom­position has been found. The decomposition has been sensitized by the incorporation of cyanamide ion into the crystal lattice. The sensitized azide was found to explode at a much lower temperature than the unsensitized azide. At temperatures too low for explosion it decomposes at a much greater rate, though the kinetics are unchanged and no significant change has been found in the energy of activation. A mechanism for the reaction is put forward and the great difference between the behaviour of silver and thallium azides and that of the alkali-metal azides explained in terms of the physical properties of the crystal lattices. A theoretical calculation of the activation energies for the decomposition of the azides is made.