The latter may be formed by using certain additives, such as halogen-containing organic and/or oxygencontaining inorganic compounds. Effect of PTFE as a chemical activator of the combustion synthesis in various low-caloric systems was reported [27,30]. These compounds may react with solid reactant (s) and form gaseous compounds and the same time generate large amount heat which in its turn promotes solid-state reaction. This is the basic principle of thermal and chemical activation.