The thermal stability and topotactic transition of Ti3SiC2 in vacuum,argon and air havebeen investigated by synchrotron radiation diffraction (SRD),in-situ neutron diffraction (ND)and secondary ion mass spectroscopy (SIMS).In the presence of a low oxygen partial pressuresuch as in vacuum or argon,Ti3SiC2 undergoes a surface dissociation to form non-stoichiometricTiC and/or TisSi3C at 1200 °C.In contrast,it forms non-stoichiometric surface oxides of rutile at1000 °C and cristobalite at 1300 °C when exposed to an oxygen-rich environment.Near-surfacedepth profiling of vacuum-treated Ti3SiC2 by SIMS has revealed a distinct gradation in phasecomposition and confirmed the existence of TisSi3C in solid solution with oxygen.
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