AMORPHISATION DE L'OXYNITRURE DE SILICIUM IRRADIE AUX NEUTRONS RAPIDES : ETUDE PAR SPECTROMETRIE INFRAROUGE

Les modifications du spectre d'absorption infrarouge de Si2ON2 irradié aux neutrons rapides permettent de préciser la nature des endommagements créés dans la maille. On a attribué toutes les absorptions observées dans le spectre et déterminé l'intensité intégrée des bandes du produit frais et irradié. On a mis en évidence une rupture de la liaison silicium-oxygène et les variations des structures des groupements voisins. Ces défauts ponctuels précèdent une amorphisation progressive du matériau.In this work we report measurements of the infrared absorption in fast neutron irradiated Si2ON2, correlated with the kinds of damages induced in the crystal cell. First we have assigned every observed absorption bands of the spectrum and obtained the integrated intensity for the fresh and irradiated material, then we have clearly shown a break in silicium-oxygen bond and variations i n the nearest structures. These point defects precede a progressive amorphization of the bulk

FT-IR study of the surface properties of silicon nitride

The surface properties of a largely amorphous Si3N4 sample prepared by nitridation with ammonia of amorphous silica at 1300\ub0C have been studied by Fourier Transform Infrared Spectroscopy using adsorbed molecules such as water, benzene, acetonitrile, acetone, ammonia, triethylamine, chloroform, formic acid and methanol. The presence on the surface and the activity of SiOH, Si2NH and SiH groups as well as of basic nitrogens bonded to three silicon atoms has been evidenced. The development of an increased surface basic character of silicon nitride with respect to silica has also been pointed out. \ua9 1986