Here is an excerpt from an email exchange that was linked to in that diary:
QUESTION (Rancourt): The exothermic peak in the DSC traces occurs at a
temperature (420 C) approximately 90 C below the temperature for
the thermite reaction. No explanation is proposed for this. Chemical
activation energies of known reactions cannot be so sample
dependent, whether nano-sized or not. This is not the thermite
ANSWER (Harrit): We do not claim that the red/grey chips are the same
material as Tillotson et al. described. Actually, we are pretty sure it is
NOT for the same - for reasons given above.
Your statement about activation energies is nonsense. An activation
energy is a thermodynamic quantity referring to standard conditions
in solution or in the gas phase. That some people take this lightly is
another matter. But to postulate a unique correlation between
ignition temperature and activation energy in a two-phase solid
reaction is ridiculous. Well, maybe you can expect a lower ignition
temperature the smaller the particles – as observed.
Of course, all samples have a different ignition temperature (Fig. 19),
and of course, different preparations with different compositions will
have different ignition temperatures.
And what do you mean by “the temperature for the thermite
reaction”? You are going to have a very hard time if you try to search
the literature for a well-defined ignition temperature of conventional
thermite mixtures. Please, provide a reference next time you come
up with such a statement.