We studied titanium carbide (TiC) at pressures up to 38(1) GPa using in sit
u powder X-ray diffraction and observed a phase transformation from the NaC
l-type cubic structure (B1) to a rhombohedral structure at a pressure above
18 GPa at 300 K under a quasi-hydrostatic environment.
For the rhombohedral phase we obtained the following data:
Isothermal bulk modulus K-300.1 (GPa) 248(4)
Pressure derivative K-300.1' 6.5(3)
For the cubic phase of TiC, we obtained K-300.1 = 235(2) GPa and K-300.1' =
6.5 which is in good agreement with recent results. Ab initio calculations
support the possibility of a cubic to rhombohedral phase transition. The c
alculated bulk modulus K-300.1 = 220 GPa is close to the experimental one.
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