Phase Relations of SiC at High Pressures and High Temperatures

The high-pressure melting behavior of SiC is not well constrained, despite its likelihood as one of the major components in carbon-rich exoplanets. Using the laser-heated diamond-anvil cell (LHDAC) this study investigates the melting of SiC over a range of pressures relevant to planetary interiors. Both optical, spectroscopic and x-ray diffraction data of post-heated samples indicate that SiC melts incongruently at high pressure following a positive Clapeyron slope. These melting properties imply that the interior of a carbon-rich planet may have a more complicated layering structure than previously thought, a characteristic that will in turn affect the interior dynamics.