Synthesis and high-temperature evolution of single-phase amorphous Si–Hf–N ceramics ☆
Synthesis and high-temperature evolution of single-phase amorphous Si–Hf–N ceramics ☆
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DOI：
10.1016/j.jeurceramsoc.2015.01.026
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发表时间：
2015-07
影响因子：
5.7
通讯作者：
Cong Zhou;X. Gao;Yeping Xu;G. Buntkowsky;Y. Ikuhara;R. Riedel;E. Ionescu
中科院分区：
文献类型：
--
作者：
Cong Zhou;X. Gao;Yeping Xu;G. Buntkowsky;Y. Ikuhara;R. Riedel;E. Ionescu
以四（二甲氨基）铪（IV）（TDMAH）为前驱体，采用单源氨解法制备了新型非晶态聚合物Si-Hf-N陶瓷。将制备的Si-Hf-N材料在1100 °C ~ 1800 °C范围内的不同温度下在氮气气氛中退火，并研究了其化学组成、晶化行为和相演变。单源前体在氨环境中在1000 °C下热处理时转化为非晶单相陶瓷，并且即使在氮气氛中在1400 °C下退火后仍保持非晶。电子显微镜研究表明，退火的高度均匀的单相Si-Hf-N诱导Hf的局部富集（集群），导致非晶HfN/SiNx纳米复合材料。在1600 °C的氮气中退火导致HfN和Si 3 N4的结晶。本工作的结果强调了从合适的单源前体方便地制备硅-金属-氮化物纳米复合材料。
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/SiNxnanocomposites. Annealing in nitrogen at 1600 °C leads to the crystallization of HfN and Si3N4. The results of the present work emphasize a convenient preparative access to silicon–metal–nitride nanocomposites from suitable single-source precursors.