Energetics and Structure of Polymer-Derived Si-(B-)O-C Glasses: Effect of the Boron Content and Pyrolysis Temperature - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Journal of the American Ceramic Society Année : 2014

Energetics and Structure of Polymer-Derived Si-(B-)O-C Glasses: Effect of the Boron Content and Pyrolysis Temperature

Résumé

The structure and properties of polymer-derived Si-(B-)O-C glasses have been shown to be significantly influenced by the boron content and pyrolysis temperature. This work determined the impact of these two parameters on the thermodynamic stability of these glasses. High-temperature oxide melt solution calorimetry was performed on a series of amorphous samples, with varying boron contents (0-7.7 at.%), obtained by pyrolysis of precursors made by a sol-gel technique. Thermodynamic analysis of the calorimetric results demonstrated that at a constant pyrolysis temperature, adding boron makes the materials energetically less stable. While the B-containing glasses pyrolyzed at 1000 degrees C were energetically less stable than the competitive crystalline components, increasing the pyrolysis temperature to 1200 degrees C led to their enthalpic stability. Si-29 and B-11 MAS nuclear magnetic resonance (NMR) spectroscopy measurements on selected samples confirmed a decrease in the concentrations of mixed Si-centered SOiC4-i and B-centered BOjC3-j bonds at the expense of formation of SiO4 and B (OSi)(3) species (indicating a tendency toward phase separation) when the boron content and pyrolysis temperature increased. In light of the findings from calorimetry and NMR spectroscopy, we propose a structure-energetic relationship in Si-(B-) O-C glasses.

Domaines

Matériaux

Dates et versions

hal-01275053 , version 1 (16-02-2016)

Identifiants

Citer

Amir H. Tavakoli, Renzo Campostrini, Christel Gervais, Florence Babonneau, Joachim Bill, et al.. Energetics and Structure of Polymer-Derived Si-(B-)O-C Glasses: Effect of the Boron Content and Pyrolysis Temperature. Journal of the American Ceramic Society, 2014, 97 (1), pp.303-309. ⟨10.1111/jace.12658⟩. ⟨hal-01275053⟩
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