材料科学
纳米颗粒
尿素
热解
氮气
陶瓷
碳热反应
退火(玻璃)
微观结构
氯化物
化学工程
核化学
纳米技术
有机化学
冶金
化学
碳化物
工程类
作者
Guang Zeng,Ping Xu,Zeng Chen,Qizhong Huang,Zhean Su
出处
期刊:Materials
[MDPI AG]
日期:2023-06-16
卷期号:16 (12): 4426-4426
摘要
HfCxN1-x nanoparticles were synthesized using the urea-glass route, employing hafnium chloride, urea, and methanol as raw materials. The synthesis process, polymer-to-ceramic conversion, microstructure, and phase evolution of HfCxN1-x/C nanoparticles were thoroughly investigated across a wide range of molar ratios between the nitrogen source and the hafnium source. Upon annealing at 1600 °C, all precursors demonstrated remarkable translatability to HfCxN1-x ceramics. Under high nitrogen source ratios, the precursor exhibited complete transformation into HfCxN1-x nanoparticles at 1200 °C, with no observed presence of oxidation phases. In comparison to HfO2, the carbothermal reaction of HfN with C significantly reduced the preparation temperature required for HfC. By increasing the urea content in the precursor, the carbon content of the pyrolyzed products increased, leading to a substantial decrease in the electrical conductivity of HfCxN1-x/C nanoparticle powders. Notably, as the urea content in the precursor increased, a significant decrease in average electrical conductivity values was observed for the R4-1600, R8-1600, R12-1600, and R16-1600 nanoparticles measured at a pressure of 18 MPa, yielding values of 225.5, 59.1, 44.8, and 46.0 S·cm-1, respectively.
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