Microstructure of carbon fibers prepared laser CVD

A layered plate-like microstructure was observed parallel to the deposition surface in carbon fibers prepared by laser CVD from methane at pressures lower than 1 atm. Periodic cracks existed in the fibers parallel to the layers. Cracking was likely caused by thermally induced stress, and by weak bonds between layers. In fibers deposited at higher temperatures, the volcano effect was observed. A striped structure composed of loosely piled graphitic plates was observed along the axial direction in the center part of the fibers.