Figure 4
Decomposition onset temperature for calcite (black squares) and kaolinite (inset, blue circles) vs. particle size. Note that the two graphs are plotted on very different scales, with the kaolinite enlarged to show that there is a measurable difference with particle size, but it is small in comparison to calcite. The effects of particle size on decomposition temperature are larger for more crystalline particles (calcite) than for agglomerates of smaller particles (kaolinite). Samples were run at 30 mbar instrument pressure, 3 sccm He carrier gas flow rate, and a 35°C/minute ramp rate.