In-situ TEM studies on stick-slip friction characters of sp2 nanocrystallited carbon films

Carbon films with two different kinds of sp2 nanocrystallited structure were investigated to study the stick-slip friction with the in-situ and ex-situ tests. In-situ transmission electron microscope (TEM) observation and nanofriction tests revealed that the origins of stick and slip varied with shear stress and film deformation. At the stick stage, shear stress gradually increased with the contact strengthened until reached the shear strength to break the interfacial adhesion; at the slip stage, the shear stress decreased and accompanied with film deformation. During the sliding process, adhesive deformation resulted in the large stick-slip step while ploughing deformation led to a smoother step. Ex-situ nanofriction tests on a series of sp2 nanocrystallited carbon films with different irradiation energies showed the expected sliding behavior with the in-situ results. This study first clarified the mechanism of stick-slip friction with the in-situ TEM observation, which plays the important role for the micro and nano application of sp2 nanocrystallited carbon films.

Influence of different types of solvents on morphology, optical and conductive properties of PCBM films

The article deals with the influence of various types of solvents on the spectral characteristics and conductive properties of films [6,6]-methyl phenyl-C61-butyric acid, precipitated from solutions. It is clearly shown that the effect of the nature of the solvent affects the morphology of the film surface. Analysis of the spectra of the optical range showed the presence of a maximum of the absorption coefficient in the frequency range of 340-490 nm. The calculation of the optical bandgap clearly demonstrates the possibility of modernizing the atomic structure of films by using various types of solvents. A study of the current-voltage characteristics showed the presence of a photocurrent in carbon films deposited with dichloromethane, toluene, and chloroform.

Study of the influence of diamond-like carbon film deposition technology on the change of its physical and mechanical characteristics

The paper presents the results of testing the technology of deposition of diamond-like carbon films on the surface of stainless steel substrates at different process parameters, a quantitative assessment of the sp3 bond content and the physical and mechanical characteristics of the coatings obtained, a conclusion about the influence of the deposition process technological parameters on these characteristics is formulated.