526 / 2019-03-19 21:23:54

Stability of Zirconium Carbide under High Pressure and High Temperature

Zirconium carbide; High temperature; High pressure; phase transition

全体主题 > High Pressure Physics and Materials Science

Zirconium carbide (ZrC) is an important material, because of its industrial applications like cutting tools, magnetic storage devices and nuclear fusion power plant at various extreme conditions. However, the phase stability of ZrC, especially under high-pressure and/or high-temperature, has not been experimentally explored,. In this study, in situ high-pressure x-ray-diffraction experiments up to 154 GPa was carried out on ZrC at room temperature using a diamond-anvil cell. The refinement shows that ZrC remains very stable rather than undergoing the structural phase transition from B1 to B2 as predicted in various simulations. Fitting the volume data using the third-order Birch-Murnaghan equation of state, a bulk modulus K0 = 210 ± 1 GPa with pressure derivative K0′ fixed at 4 was obtained. During further in situ high pressure laser heating XRD experiments, we also investigated the structural stability of ZrC under both high-pressure and high-temperature. The B1-ZrC is stable up to 2000 K and 40 GPa. But at high pressure and high temperature, ZrC is extremely active to react with even trace amount of water in the environment to form zirconia oxide and methane.