Chemical vapor deposition of thin graphite films of nanometer thickness

Well-ordered graphite films with a thickness of a few graphene layers have been grown on Ni substrates by chemical vapor deposition (CVD) from a mixture of hydrogen and methane activated by a DC discharge. According to Auger, Raman and scanning tunneling microscopy (STM) data the CVD graphite film thickness is about 1.5 +/- 0.5 nm. The graphene layers were perfectly adhered to the substrate surface except for upthrusted ridges of a few tens of nanometers in height. STM has revealed an atomically smooth surface with the atomic arrangement typical of graphite between the ridges. A difference in the thermal expansion coefficients of nickel and graphite is considered as a reason for the ridge formation. (c) 2007 Elsevier Ltd. All rights reserved.