Synthesis and high-temperature evolution of single-phase amorphous Si–Hf–N ceramics. Issue 7 (July 2015)

• Record Type: Journal Article
• Authors: Zhou, C.; Gao, X.; Xu, Y.; Buntkowsky, G.; Ikuhara, Y.; Riedel, R.; Ionescu, E.
• Is Part Of: Journal of the European Ceramic Society. Volume 35:Issue 7(2015:Jul.)
• Page Start: 2007
• Page End: 2015
• Publication Date: 2015-07
• Subjects: Polymer-derived ceramic -- Silicon–hafnium–nitride ceramic -- Nanocomposite -- Silicon nitride -- Hafnium nitride; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2015.01.026
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: Novel amorphous polymer-derived Si–Hf–N ceramics were prepared via ammonolysis of single-source precursors which were synthesized by the chemical reaction of a commercially available perhydropolysilazane (PHPS) with different amounts of tetrakis(dimethylamido) hafnium(IV) (TDMAH). The prepared Si–Hf–N materials were annealed in nitrogen atmosphere at different temperatures ranging from 1100 °C to 1800 °C and investigated with respect to their chemical composition, crystallization behavior and phase evolution. The single-source precursors converted upon heat treatment in ammonia environment at 1000 °C into amorphous single-phase ceramics and remained amorphous even after annealing at 1400 °C in nitrogen atmosphere. Electron microscopy investigation showed that the annealing of the highly homogeneous single-phase Si–Hf–N induces local enrichment (clustering) of Hf, leading to amorphous HfN/SiN x nanocomposites. Annealing in nitrogen at 1600 °C leads to the crystallization of HfN and Si3 N4 . The results of the present work emphasize a convenient preparative access to silicon–metal–nitride nanocomposites from suitable single-source precursors.