TY - JOUR
T1 - Thermodynamic control of phase composition and crystallization of metal-modified silicon oxycarbides
AU - Ionescu, E.
AU - Terzioglu, C.
AU - Linck, C.
AU - Kaspar, J.
AU - Navrotsky, A.
AU - Riedel, R.
N1 - Copyright:
Copyright 2013 Elsevier B.V., All rights reserved.
PY - 2013/6
Y1 - 2013/6
N2 - Silicon oxycarbides modified with main group or transition metals (SiMOC) are usually synthesized via pyrolysis of sol-gel precursors from suitable metal-modified orthosilicates or polysiloxanes. In this study, the phase composition of different SiMOC systems (M = Sn, Fe, Mn, V, and Lu) was investigated. Depending on the metal, different ceramic phases formed. For M = Mn and Lu, MOx/SiOC ceramic nanocomposites were formed, whereas other compositions revealed the formation of M/SiOC (M = Sn), MSix/SiOC (M = Fe) or MCx/SiOC (M = V) upon pyrolysis. The different phase compositions of the SiMOC materials are rationalized by a simple thermodynamic approach which generally correctly predicts which type of ceramic nanocomposite is expected upon ceramization of the metal-modified precursors. Calculations show that the thermodynamic stability of the MOx phase with respect to that of the C-O system is the most important factor to predict phase formation in polymer-derived SiMOC ceramic systems. A secondary factor is the relative stability of metal oxides, silicates, carbides, and silicides.
AB - Silicon oxycarbides modified with main group or transition metals (SiMOC) are usually synthesized via pyrolysis of sol-gel precursors from suitable metal-modified orthosilicates or polysiloxanes. In this study, the phase composition of different SiMOC systems (M = Sn, Fe, Mn, V, and Lu) was investigated. Depending on the metal, different ceramic phases formed. For M = Mn and Lu, MOx/SiOC ceramic nanocomposites were formed, whereas other compositions revealed the formation of M/SiOC (M = Sn), MSix/SiOC (M = Fe) or MCx/SiOC (M = V) upon pyrolysis. The different phase compositions of the SiMOC materials are rationalized by a simple thermodynamic approach which generally correctly predicts which type of ceramic nanocomposite is expected upon ceramization of the metal-modified precursors. Calculations show that the thermodynamic stability of the MOx phase with respect to that of the C-O system is the most important factor to predict phase formation in polymer-derived SiMOC ceramic systems. A secondary factor is the relative stability of metal oxides, silicates, carbides, and silicides.
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U2 - 10.1111/jace.12327
DO - 10.1111/jace.12327
M3 - Article
AN - SCOPUS:84878730018
VL - 96
SP - 1899
EP - 1903
JO - Journal of the American Ceramic Society
JF - Journal of the American Ceramic Society
SN - 0002-7820
IS - 6
ER -