Marina Serantoni

Electrochemical and morphological study of the effect of polymerization conditions on poly(tetrathiophene) with emphasis on carbon fiber microelectrodes: A cyclic voltammetry and atomic force microscopy study

Electropolymerization of tetrathiophene was carried out in various solvents on carbon fiber microelectrodes and platinum electrodes. Acetonitrile, dichloroethane and propylene carbonate were investigated as solvent systems for film formation, and solvent effect as well as the effect of other experimental conditions (scan rate, supporting electrolyte) on the electropolymerization has been discussed on the basis of the electropolymerization mechanism. Surface morphology was investigated by atomic force microscopy (AFM). Carbon fiber electrodes were found to be an effective microelectrode system for the electropolymerization of tetrathiophene, which was compared with polyterthiophene growth on carbon fibers.

Nanoindentation combined with scanning force microscope for characterization of mechanical properties of carbon nitride thin films

Scanning force microscope (SFM) imaging of the residual indent, in conjunction with the nanoindentation results, provides a better understanding of the response of a material to indentation at small scales. The true residual contact area directly measured from the SFM images can subsequently be used to recalculate the hardness of the material measured by nanoindentation more accurately. In this study, nanoindentation with SFM has been used to investigate the mechanical properties of thin CN films deposited by RF magnetron sputtering on silicon (1 0 0) substrates. Hardness was determined at different loads and depths from nanoindentation using the Oliver and Pharr method. The indents were imaged using SFM and true residual contact areas as well as hardness values were determined. Residual indentation depths from SFM and from nanoindentation were in agreement and hardness values obtained by SFM agreed with the hardness measured by the Oliver and Pharr method.