Growth of Graphite Spheres in Liquid Nickel

Flake graphite has been found to transform into spherical graphite in liquid nickel. Graphite spheres with diameters ranging from 300 to 1μm have been extracted by acid erosion of the nickel, and have been characterized using various techniques. The surface of graphite spheres shows disordered atomic stacking and defects. This is in agreement with the Raman spectrum result which shows that the structure of graphite spheres consists of loose disordered center and ordered graphite shells from interior to exterior. The growth mechanism of the graphite spheres is briefly discussed.