Exothermic Surface Reactions on Sintered Graphite Upon Exposure to CO2 Plasma Created in Microwave Discharge

Microwave (MW) discharges in a resonant cavity are suitable for sustaining gaseous plasma. An appropriate matching allows for optimization of discharge efficiency so the MW power is used for heating plasma in a small volume where a sample is placed. Such concentrated power dissipation allows for creation of gaseous plasma with high dissociation and moderate ionization fractions. In the case when plasma is created in CO₂ atmosphere, the molecules are highly dissociated and O radicals interact chemically with sintered graphite causing significant etching. Both chemical and physical surface interactions induce extensive heating of samples so such a discharge is suitable for modification of solid materials at elevated temperatures.