Synthesis of Diamond-Like Carbon Spheres under High Temperature and High Pressure

Carbon microspheres prepared using the chemical vapor deposition method were treated under high-pressure and high-temperature conditions of about 8 GPa and 1 600 ℃.Based on the volume variation of diamond and molybdenum with the pressure and temperature, we designed and optimized the temperature-pressure path for sample treatments, thereby reducing the residual stress caused by the difference between the diamond's and the molybdenum's elastic modulus and thermal expansion.The Raman spectrum show that the samples have an obvious 1 332 cm^-1 diamond characteristic peak, and the high-temperature and high-pressure treatments effectively eliminate the trans-polyacetylene in the initial diamond-like carbon microsphere.The scanning electron microscope results show that the samples exhibit good sphericity, with an average diameter of 2 mm, the diamond-like film surface has an average grain size of 100 nm, and the film thickness is about 20 μm.The atomic force microscope test results show that the surface roughness is 647 nm.