Hafnium carbonitride (HfCxN1–x) ceramics have drawn considerable interest due to their exceptional mechanical and thermophysical properties. Herein, we report a novel single-source precursor with Hf–N bonds as the main chain and fabricate HfCxN1–x ceramics after pyrolysis of the precursor. The synthesis, ceramic conversion, and microstructural evolution of the single-source precursor as well as the derived HfCxN1–x ceramics treated under various atmospheres were investigated. The results indicate that in an argon atmosphere, the nitrogen content within HfCxN1–x decreases with rising temperature. While under a nitrogen atmosphere, the high concentration of N2 facilitates the rapid conversion of HfO2 to Hf7O8N4, which subsequently promotes the transformation of the HfCxN1–x solid solution ceramics. During this process, there is also an inhibitory effect of N2 on the tendency of HfN into HfC. Moreover, the desired chemical composition of HfCxN1–x can be regulated by adjusting the N2 concentration in the heat treatment atmosphere. The present work proposes a novel strategy for the single-source precursor-derived carbonitride ceramics and provides a deep understanding of the preparation and property modulation of HfCxN1–x ceramics.

中文翻译：

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从分子前驱体到超高温陶瓷：碳氮化铪纳米陶瓷的新型合成


碳氮化铪 （HfCxN1–x） 陶瓷因其卓越的机械和热物理性能而引起了相当大的兴趣。在此，我们报道了一种以 Hf-N 键为主链的新型单源前驱体，并在前驱体热解后制备了 HfCxN1-x 陶瓷。研究了在各种气氛下处理的单源前驱体以及衍生的 HfCxN1-x 陶瓷的合成、陶瓷转化和微观结构演变。结果表明，在氩气气氛中，HfCxN1-x 中的氮含量随着温度的升高而降低。在氮气气氛下，高浓度的 N2 促进了 HfO2 向 Hf7O8N4 的快速转化，从而促进了 HfCxN1-x 固溶体陶瓷的转化。在此过程中，N2 对 HfN 转化为 HfC 的趋势也有抑制作用。此外，可以通过调整热处理气氛中的 N2 浓度来调节 HfCxN1-x 所需的化学成分。这项工作为单源前驱体衍生的碳氮化物陶瓷提出了一种新的策略，并为 HfCxN1-x 陶瓷的制备和性能调控提供了深入的理解。