Aluminum-27 and Silicon-29 Solid-State Nuclear Magnetic Resonance Study of Silicon Carbide/Aluminum Nitride Systems:  Effect of Silicon/Aluminum Ratio and Pyrolysis Temperature

• Published in: Chemistry of materials Vol. 10; no. 4; pp. 1003 - 1009
• Main Authors: Verdecia, G, O'Brien, K. L, Schmidt, W. R, Apple, T. M
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.04.1998
• Subjects: Applied sciences; Building materials. Ceramics. Glasses; Ceramic industries; Chemical industry and chemicals; Exact sciences and technology; Structural ceramics; Technical ceramics; Aluminium Nitrides; Pyrolysis; Silicon Carbides; Silazane polymer; Temperature effect; NMR spectrometry; Manufacturing; Solid solution; Precursor; Non oxide ceramics; Structural ceramic; Crystalline structure
• ISSN: 0897-4756; 1520-5002
• DOI: 10.1021/cm970435u

Three series of SiC/AlN samples were prepared by pyrolysis of “poly(aluminosilazane)”, the product of the reaction between hexamethylcyclotrisilazane and triethylaluminum. The Si/Al ratio was varied for one series (with constant pyrolysis temperature) and the pyrolysis temperature was varied for the other two series, with Si/Al = 1 and 3. 27Al and 29Si magic angle spinning NMR were used to analyze these samples in terms of coordination number, nearest neighbor atoms, and crystallinity. NMR results indicate that higher crystallinity and phase separation into discrete SiC and AlN crystallites accompany an increase in pyrolysis temperature. Disorder and increased heterogeneity in connectivity are observed with increasing Si/Al ratio of the initial reactants.