[1] Univ Western Ontario, Dept Chem, London, ON N6A 5B7, Canada
[2] Univ Wisconsin, Canadian Synchrotron Radiat Facil, Ctr Synchrotron Radiat, Stoughton, WI 53589 USA
[3] City Univ Hong Kong, Dept Appl Phys & Mat Sci, Ctr Super Diamond & Adv Films, Hong Kong, Hong Kong, Peoples R China