Optical indices and transport scattering coefficient of pyrolytic boron nitride: a natural thermal barrier coating for solar shields

Domingos de Sousa Meneses (1) , Marianne Balat-Pichelin (2) , Olivier Rozenbaum (3, 4) , Leire del Campo (1) , Patrick Echegut (1)

1 CEMHTI - Conditions Extrêmes et Matériaux : Haute Température et Irradiation
2 PROMES - Procédés, Matériaux et Energie Solaire
3 ISTO - Institut des Sciences de la Terre d'Orléans - UMR7327
4 Milieux Poreux - UMR7327

Absorption and scattering properties of pyrolytic boron nitride (pBN) have been characterized by infrared spectroscopy. The strong dielectric anisotropy predicted by first principles calculations is confirmed by measurements performed on a highly oriented pBN sample. Optical properties of textured samples elaborated by chemical vapor deposition were identified from normal hemispherical reflectance and transmittance spectra by applying modified two-flux and four-flux transport models. It is also shown that coating carbon–carbon composites used to build solar shields with a pBN layer having an optimal thickness could improve the protection performance.

Domains: Sciences of the Universe [physics]

Domingos de Sousa Meneses, Marianne Balat-Pichelin, Olivier Rozenbaum, Leire del Campo, Patrick Echegut. Optical indices and transport scattering coefficient of pyrolytic boron nitride: a natural thermal barrier coating for solar shields. Journal of Materials Science, 2016, 51 (9), pp.4660-4669. ⟨10.1007/s10853-016-9781-2⟩. ⟨insu-01280535⟩