Hafnium carbonitride (HfCN) is an ultra-high temperature ceramic (UHTC) mixed anion compound composed of hafnium (Hf), carbon (C) and nitrogen (N).
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3D model (JSmol)
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Properties | |
CHf2N | |
Molar mass | 204.51 g/mol[1] |
Appearance | black odorless powder |
Density | 12.65–13.073 g/cm3[2] |
Melting point | 4,110 °C (7,430 °F; 4,380 K)[3] |
insoluble | |
Thermal conductivity | 19–24 W⋅m−1⋅K−1[2] |
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
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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),[3] highest known for any material.[3][4][5] Another approach based on the artificial neural network machine learning pointed towards a similar composition — HfC0.76N0.24.[3] Experimental testing conducted in 2020 has confirmed a melting point above 4,000 °C (7,230 °F; 4,270 K),[4][5] substantiating earlier predictions made with atomistic simulations in 2015.[6]
The HfCxN1−x has been assessed to possess the following properties:[2]