Cathode erosion, methods

The plasma parameters of f=5 cm mln (at STP), p=0.015 torr and w 100 watts are the same In all cases. The ESCA data Immediately affirm that both molybdenum and copper are Incorporated Into the polymer films although as previously noted the method of cathode erosion must be different In the two cases, (chemical plasma etching versus physical sputtering). Consideration of the relative signal Intensities, corrected for the total relative sensitivities of the core levels, derived from standard homogeneous samples, allows estimates of the empirical formulae to be written for these materials as follows [C3F4 oOo.6 °0.3ln... 

An interesting n thod similar to Matsumoto s has been proposed by Wickens for boron carbide synthesis. The experimental arrangement is shown Fig. 81 a hi intensity arc is struck between a graphite cathode and a composite consumable anode made of boron oxide or sodium borate which are more readily available and cheaper than boron trichloride. B4C was obtained by this method, but the author indicates that the power comsumption (kWh/kg B4C) was high owing to insufficient erosion of the consumable anode. 

It is possible to determine the four contributions to the total material loss rate by the following experimental principles the total material loss rate Wt is determined by weighing the specimen before and after exposure under combined erosive and corrosive conditions. The sum of Wc and Wce (the corrosion components) can be measured by electrochemical methods during the same exposure (the methods described in Section 9.2 can also be used under erosive conditions). We is determined by weighing the specimen before and after exposure in special tests where corrosion is eliminated by cathodic protection (or possibly by oflier means) but otherwise under the same conditions as in the former experiments. Wc can be measured electrochemically in tests like the original ones but with all solid particles excluded. Finally, the synergy components, Wce and Wec, can be derived from Equation (7.9) and the mentioned experiments. 

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