Two synthesis routes of organometallic precursors for the elaboration of SiCNYO pre‐alloyed nanopowders

Abstract

International audienceTwo routes were simultaneously investigated to prepare organometallic precursors. They were characterized by NMR and FTIR techniques. In the first route, yttrium acetate was silylated by trimethylchlorosilane before its dissolution in hexamethydisilazane. That leads to a liquid precursor containing Si–C–N–Y–O–H elements. In the second route, a precursor with the same elements was elaborated by dissolution of an amminolysed yttrium compound in tetramethyldisiloxane. The amminolysed yttrium compound was obtained through the amminolysis of the yttrium trichloride by triethylamine [N(C2H5)3]

Influence of H2/NH3 mixtures on the composition of SiCNYO and SiCNAl(O) nanopowders

“…2,13 The Y precursor was synthesized by dissolving 2 g silylated Y acetate (Y(O 2 C 5 SiH 11 ) 3 ) in 50 mL HMDS [(CH 3 ) 6 Si 2 NH)], 14 and the SiCNAlH precursor was obtained by reaction between 50 mL HMDS and 1.8 mL trimethylaluminum (Al(CH 3 ) 3 ). 2 The different precursors were synthesized under flowing Ar (previously purified through CaSO 4 [drierite indicator] and P 2 O 5 .…”

“…Especially, in the case of the SiCNYOH precursor, the Y acetate was silylated before its dissolution in HMDS, which could explain the different Si environments in the SiCNYO and SiCNAl(O) powders. 2,14 For the SiCNYO powders ( Fig. 5(a)), the spectrum shows a broad peak from −10 to −60 ppm, with an apex at −50 ppm, which indicates a N-rich environment such as SiN 4 the second broad peak, with low intensity at −110 ppm, corresponds to an SiO 4 environment and could be assigned to silica or a silicate.…”