Hafnium carbonitride
| Identifiers | |
|---|---|
3D model (JSmol) |
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| Properties | |
| CHf2N | |
| Molar mass | 204.51 g/mol |
| Appearance | black odorless powder |
| Density | 12.65–13.073 g/cm3 |
| Melting point | 4,110 °C (7,430 °F; 4,380 K) |
| insoluble | |
| Thermal conductivity | 19–24 W⋅m−1⋅K−1 |
| Structure | |
| Cubic crystal system, cF8 | |
| Fm3m, No. 225 | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references | |
Hafnium carbonitride (HfCN) is an ultra-high temperature ceramic (UHTC) mixed anion compound composed of hafnium (Hf), carbon (C) and nitrogen (N).
Ab initio molecular dynamics calculations have predicted the HfCN (specifically the HfC0.75N0.22 phase) to have a melting point of 4,110 ± 62 °C (4,048–4,172 °C, 7,318–7,542 °F, 4,321–4,445 K), the highest known for any material. Another approach based on the artificial neural network machine learning pointed towards a similar composition — HfC0.76N0.24. Experimental testing conducted in 2020 has confirmed a melting point above 4,000 °C (7,230 °F; 4,270 K), substantiating earlier predictions made with atomistic simulations in 2015.