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Structural Characterization and High‐Temperature Behavior of Silicon Oxycarbide Glasses Prepared from Sol‐Gel Precursors Containing Si‐H Bonds
Author(s) -
Sorarù Gian Domenico,
D'Andrea Gennaro,
Campostrini Renzo,
Babonneau Florence,
Mariotto Gino
Publication year - 1995
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1995.tb08811.x
Subject(s) - materials science , silicon , crystallite , chemical engineering , amorphous solid , crystallization , raman spectroscopy , magic angle spinning , sol gel , phase (matter) , crystallography , nanotechnology , nuclear magnetic resonance spectroscopy , chemistry , organic chemistry , physics , optics , engineering , metallurgy
Silicon oxycarbide glasses have been synthesized by inert atmosphere pyrolysis at 1000°C of gel precursors obtained by cohydrolysis of triethoxysilane, HSi(OEt) 3 , and methyl‐diethoxysilane, HMeSi(OEt) 2 . The oxycarbide structures have been carefully characterized by means of different techniques such as 29 Si magic angle spinning nuclear magnetic resonance (MAS‐NMR) and Raman spectroscopies, X‐ray diffraction (XRD), and chemical analysis. Experimental results clearly indicate that, depending on the composition of the starting gels, the resulting oxycarbide glass either is formed by a pure oxycarbide phase or contains an extra carbon or silicon phase. By increasing the temperature up to 1500°C, the oxycarbide glasses display compositional and weight stability; however, the amorphous network undergoes structural rearrangements that lead to the precipitation of nano‐sized β‐SiC crystallites into amorphous silica. Crystallization of metallic silicon is also clearly observed at 1500°C for the samples in which the presence of Si‐Si bonds was postulated at 1000°C.