At the beginning of the experiment, a purge with the
neutral gas (nitrogen or argon) was performed in order
to ensure an inert atmosphere inside the chamber. This step
was carried out without concentrated solar radiation illu-
mination. Then, either N2 or Ar was continuously intro-
duced into the chamber with a flow of 1 Nl/min for the
remaining of the experiment. The illumination started with
the gradual opening of the shutter until the reaction tem-
peratures were reached. The experiments were carried out
with solar Direct Normal Irradiance (DNI) values close
to the 900 W/m2
the SiO2/C nanocomposite synthesis, and 1500 C for SiC
synthesis. After each synthesis step, the powder is collected
for further characterization.
. Average temperatures were 700 C, for