Determining the heat of a surface plasmochemical reaction by scanning calorimetry

A method for experimental determination of the heat of an exothermic reaction, which proceeds on a solid surface under the action of a chemically active plasma and is accompanied by the production of volatile compounds, is proposed. Scanning calorimetry in a discharge is used in order to determine the contribution due to the heat release of the chemical reaction to the total heat flux onto the surface. It is shown how necessary it is to consider the contributions of different heat exchange mechanisms when determining the reaction heat in the case of a significant difference between the temperatures of the active and inert calorimeters. The heat of the exothermic chemical reaction of atomic fluorine with a unit mass of single-crystal silicon in a CF4 + O-2 plasma is 31 +/- 2 kJ/g or 9 eV per Si atom.