The figure also shows that the integrated emission intensity, INP, decreased by ~18% over the 1900 K period. As discussed previously, INP is expected to scale like NP volume, i.e., to be proportional to M, but in this case the decrease in INP was only ~half the decrease in M. Thus, the mass-normalized emissivity gradually increased during sublimation, again suggesting that the NP continued to transform slowly toward more Si-rich composition.