Radiometric observation of melting and freezing plateaus for a series of metal-carbon eutectic points in the, range 1330°C to 1950°C

Melting and freezing plateaus were radiometrically observed for the metal-carbon eutectics Ni-C, Pd-C, Pt-C, and Ru-C, using graphite crucibles and black-body cavities. The graphite crucibles were able to withstand heat cycles without breaking. Since the crucible material is a component of the eutectic fixed-point material, the latter is inherently free of contamination from the crucible. The temperature differences between the melting and freezing plateaus were generally less than 0.1 degrees C. The method seems to be a promising way of realizing a series of practical reference points above the copper point.