A new method to prepare compositional amorphous carbon (a-C) film termed gradient pulse bias is presented. The a-C film prepared this way showed outstanding mechanical and excellent tribological properties. The hardness and reduced modulus of the film are calculated to be 66 GPa and 320 GPa respectively. A wear rate of 1.3 x 10(-8) mm(3)/N in and frictional coefficient of 0.1 was also recorded. The novel film is also compared with multilayered and single layer a-C film prepared using the same system. (C) 2007 Elsevier B.V. All rights reserved.