Curie Temperatures of the ICTA Certified Reference Materials

Abstract

The thermogravimetry reference materials certified by the International Confederation for Thermal Analysis (and distributed by the U.S. National Bureau of Standards as GM-761)[1] provide an indication of the temperature at the sample position in a thermobalance through an apparent weight change as ferromagnetism disappears. The goal at the time of certification was to provide reference points for intercomparison of data. The certification, then, provided assurance that the reference materials were homogeneous within the entire lot, tabular information concerning the values obtained by the several participants in the test program, and a discussion of the reasons for the differences. There was no attempt to establish the Curie temperature from these data. Indeed, the diversity of reported temperatures would render such a value suspect.