INVESTIGATION OF HIGH-TEMPERATURE REACTIONS ON GRAPHITE WITH RUTHERFORD BACKSCATTERING SPECTROMETRY - INTERACTION OF CADMIUM, LEAD AND SILVER WITH A PHOSPHATE MODIFIER

The depth-dependent concentration profiles of nitrate salts of Pb, Cd and Ag were observed with and without the addition of (NH4)H2PO4 chemical modifier using Rutherford backscattering spectrometry (RBS). The RBS results demonstrate that the analytes, in all the systems investigated, readily migrate (greater-than-or-equal-to 3 mum) into the pyrolytic graphite coated graphite substrate at room temperature. The stabilization of Cd and Pb with the phosphate modifier is proposed to be due to the formation of a phosphate glass. Silver did not extensively interact with the phosphate modifier and was, as a result, not stabilized.