We prepared silicate smoke by
laser ablation of a MgSiO3 target. Particle sizes were
found to be typical 10 - 50 nm as characterized by TEM.
An annealing experiment was
carried out at 1000 K.
We chose the annealing
times 13, 21 and 30 h.
From this experiment we determined
the activation energy Ea/k = 42040 +/- 150 K.
Experiment:
Silicate smoke ablated from
a MgSiO3 target that was annealed at 1000 K up to 30 h.
Spectra shifted vertically (30h:
+1000, 21 h: +500, 13 h: +500 cm²/g)
MgSiO3-smoke
annealed at 1000 K (sample "30 h") consists of crystalline forsterite
and amorphous SiO2 in the expected 1:1-Mol ratio: 2MgSiO3
---> Mg2SiO4 + SiO2.
No enstatite (MgSiO3)
component was found after the annealing process.