A high-pressure study of HfC and nano-crystalline TiC by X-ray diffraction and density functional theory calculations.

The equation of state (EOS) of HfC and nanosized TiC at high pressure has been studied by means of synchrotron radiation X-ray diffraction (XRD) in a diamond anvil cell (DAC) at ambient temperature, and density functional theory (DFT) calculations. XRD analysis showed that the cubic structure of HfC and nanosized TiC maintained to the maximum pressures. The XRD data yield a bulk modulus K 0 = 2 8 6. 2 (4. 8) GPa with K 0 ′ = 3. 6 5 (0. 3 1) of HfC. In addition, the bulk modulus of nanosized TiC derived from XRD data is K 0 = 2 8 2. 9 (2. 1) GPa with K 0 ′ = 3. 9 5 (0. 1 4). [ABSTRACT FROM AUTHOR]