Scanning tunneling microscopy of diamond-like nanocomposite films

Abstract

Scanning tunneling microscopy is used in the present investigation to study metal containing diamond-like nanocomposites, viz. (a-C:H)/(a-Si:O)/Me films. By comparing images taken before and after samples were annealed at 450 °C for two hours, a formation of sp2-rich regions is found in Pt containing samples, in contrast to the high thermal stability shown for transition-metal containing samples. It indicates that the Pt engenders the ‘‘loosening’’ of the diamond-like matrix with a decrease in the energy barrier. These results are further confirmed by Fourier transformation infrared spectroscopy and Raman spectroscopy. The obtained micro- and nanoscale surface images and observed transformation from sp3 to sp2 bonding provides new understanding of the fundamental structure of diamond-like films.