Phase evolution, nanostructure, and oxidation resistance of polymer derived SiTiOC ceramic hybrid

Anand, Rahul; Sahoo, Sarmila; Nayak, Bibhuti B.; Behera, Shantanu K.

doi:10.1016/j.ceramint.2018.12.024

Cited by 31 publications

(12 citation statements)

References 17 publications

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“…From Figure A, it can be seen that the amorphous structure still remained after 1300°C for 5 hours in Ar, which is different from reference where β ‐SiC and TiC were formed after pyrolysis at 1300°C. In contrast, our sample Ti_PMS_Bu forms TiC and SiC at an annealing temperature of 1400°C.…”

Section: Resultscontrasting

confidence: 67%

“…Previous work on nanolaminated TiO 2 /HfO 2 /HfTiO 4 films (~0.3 μm) on SiO 2 substrate validated that the formation of HfSiO 4 is accelerated in air by the presence of TiO 2 . Moreover it is reported that TiO 2 is formed at 1200°C and at 1500°C for Ti‐alkoxide modified siloxane derived ceramics. Therefore, we consider that in our work, TiO 2 crystallites are generated during oxidation of amorphous SiTiOC following the reaction Equations () and ().…”

Section: Resultsmentioning

confidence: 98%

“…Due to the low amount of Ti‐alkoxide addition, the formation of Ti‐containing compounds, such as TiC and Ti‐oxides (TiO, TiO 2 , or Ti 3 O 5 ) . was not observed.…”

Section: Resultsmentioning

confidence: 99%

“…The electron microscopic results strongly support our observation that the type of alkoxide group, namely isopropoxide versus n-butoxide, significantly influences the phase separation as well as the crystal growth of the segregated metal oxide polymorphs. Due to the low amount of Ti-alkoxide addition, the formation of Ti-containing compounds, such as TiC 16 and Ti-oxides (TiO, TiO 2 , or Ti 3 O 5 ). 30 was not observed.…”

Section: Phases Of Ceramic Nanocomposites After Annealing At 1300°cmentioning

confidence: 99%

“…In order to increase their potential application to T ≫ 1000°C, SiOC has been modified by various elements . In particular, numerous synthesis routes to introduce Zr, Al, V, Hf, Ti, Nb, and Ta into the SiOC ceramic matrix have been developed successfully. Among them, hafnium alkoxide modified polysiloxanes followed by cross‐linking and pyrolysis can be applied to synthesize SiOC/HfO 2 ceramic nanocomposites, which are promising candidate materials for high‐temperature applications .…”

Section: Introductionmentioning

confidence: 99%

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Phase evolution of SiOC‐based ceramic nanocomposites derived from a polymethylsiloxane modified by Hf‐ and Ti‐alkoxides

Sun

Wen

et al. 2019

J Am Ceram Soc

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SiOC/HfO2‐based ceramic nanocomposites with in situ formed HfO2 nanoparticles were prepared via a single‐source precursor (SSP) approach starting from a polymethylsilsesquioxane (PMS) modified by Hf‐ and Ti‐alkoxides. By varying the alkyl‐group of the employed Hf‐alkoxides, SiOC/HfO2‐based ceramic nanocomposites with different HfO2 polymorphs formed via thermal decomposition of the SSP under the same heat‐treatment conditions. Using PMS chemically modified by Hf(OnBu)4, tetragonal HfO2 phase was formed after the synthesis at 1100°C in Ar, whereas both, tetragonal and monoclinic HfO2 nanocrystals, were analyzed when replacing Hf(OnBu)4 by Hf(OiPr)4. After oxidation of the synthesized nanocomposites in air at 1500°C, a facile formation of oxidation‐resistant HfSiO4 (hafnon) phase occurred by the reaction of HfO2 nanocrystals with silica present in the SiOC nanocomposite matrix derived from Hf(OiPr)4‐modified SSPs. Moreover the amount of hafnon is dramatically increased by the additional modification of the polysiloxane with Ti‐alkoxides. In contrast, ceramic nanocomposites derived from Hf(OnBu)4‐modified SSPs, almost no HfSiO4 is detected after oxidation at 1500°C even though in the case of Ti‐alkoxide‐modified single‐source precursor.

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Section: Resultscontrasting

confidence: 67%

Section: Resultsmentioning

confidence: 98%

“…Due to the low amount of Ti‐alkoxide addition, the formation of Ti‐containing compounds, such as TiC and Ti‐oxides (TiO, TiO 2 , or Ti 3 O 5 ) . was not observed.…”

Section: Resultsmentioning

confidence: 99%

Section: Phases Of Ceramic Nanocomposites After Annealing At 1300°cmentioning

confidence: 99%