In situ X-ray diffraction study of solid state transformations during catalytic graphitisation of amorphous carbon

Here we report on the results of an in situ X-ray diffraction study of phase transformations during catalytic graphitisation of amorphous carbon. It is demonstrated that there is unusual change of iron catalyst reflection intensity at low temperature ∼640°C. This unusual intensity change may possibly be caused by the transition of some part of metal into liquid state at low temperature. It was also shown by electron microscopy that although no graphite reflections were detected 80–90% of amorphous carbon becomes graphite after sample heating in a high temperature vacuum chamber.