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Atomic force microscopy (AFM) was used to comparatively study the structure of the bone matrix of rat tibia from an intact region with that from regions submitted to surgical injury. We used young male adult rats (Wistar), with corporal masses between 250 and 300 g. Each injury was provoked by drilling a 1.5-mm-diam hole in one cortical tibia surface. The healing course was monitored at 8 and 15 days after the injury. Atomic force microscopy images, at different magnifications, allowed the identification of the time dependence of the osteoblast activity, measured by the increase in the area of neoformed primary bone and in the organization of the collagen fibers of the bone matrix. Characterization of the natural recovery of the damaged bone tissue by AFM is potentially of great importance because it allows the comparison of natural recovery processes with those induced by medicines and other therapeutic procedures.

Diamond films of small roughness have been deposited onto thermally oxidized Si substrates by a process of anisotropic crystalline growth induced by nitrogen in a hot-filament chemical vapor deposition reactor. Ethanol (C2H5OH), diluted in hydrogen and nitrogen, was used as the source of carbon. At high concentrations, nitrogen tends to suppress the diamond growth in the 〈100〉 direction, which allows the growth of square mesoscopic-like crystals (“plates”) of large area in the directions parallel to the surface of the substrate. These plates stack upon each other, forming a thick diamond coating of uniform thickness. Analysis of the films made by micro-Raman spectroscopy and atomic force microscopy revealed that it is possible to obtain diamond coatings of high quality with a roughness comparable to that of the SiO2 at the diamond/SiO2 interface, and of nanometric roughness on the surface of the plates. A model to explain the morphology of the plates based on the microscopic mechanisms that involve the possible passivation of the (100) plane and an increase of vacancies by nitrogen is also discussed.

Micro-crystalline diamond films and nano-carbon structures in the form of wires have been grown by the introduction of argon at very high concentrations (60%–87.5% vol Ar) into the feed mixture (ethanol and hydrogen) of a hot-filament chemical vapor deposition reactor. The argon, in addition to acting as an inert diluent, also modified the kinetics of the carbon deposition process; its presence apparently minimized the deposition of intergranular hydrogenated species, induced an increase in the number of flaws between the diamond grains, increased the porosity of the films, and formed new carbon structures. Well-faceted diamond films, diamond-like carbon (DLC) balls, spongy-like wires, and multilayer structures were observed at different concentrations of Ar. Raman spectroscopy of the deposited material showed that structures of high quality diamond (60%–65% vol Ar) and carbon structures related to DLC, fullerenes and carbon nanotubes, may be deposited by this process.

Deposition of Y2O3 films on Si is of interest due to its use as a heteroepitaxial dielectric material to obtain Si‐on‐insulator or as an epitaxial buffer layer for the growth of YBa2Cu3Ox, high temperature superconductors on Si. In this investigation, Y2O3 films have been deposited in the downstream location in an electron cyclotron resonance oxygen plasma using an organometallic Y source. The reactor pressure was varied which resulted in changes in the ionic and atomic oxygen flux as well as the energetic ion bombardment of the substrate. The deposited material has been characterized by reflected high‐energy electron diffraction, x‐ray diffraction, Rutherford backscattering spectrometry, and atomic force microscopy. The majority of the films appear to be highly oriented, textured films. Deposition of the (111) phase is preferred, even on the (100) substrate.

Atomic force microscopy was used to study the morphology of crude venom from the South American rattlesnake crotalus durissus terrificus. The results indicate that the crystallized crude venom has a high surface roughness with pores of diameters around 100 nm. Coiled filamentary structures of diameters of about 200 nm and lengths greater than 1000 nm, and large concave structures of diameter around 1000 nm, have also been observed dispersed over the main solid surface of the venom. Such structures may be related to aggregates of toxic enzymes or to bacteria or both. The coiled filamentary structures appear to be entangled on the pores of the venom surface in contrast to the large concave structures, which appear not to be bonded to the principal crystallized surface.

The friction and wear behavior of chemical vapor deposition grown diamond films has been investigated under strong ultrasound conditions at the friction interface. Experiments were performed on an alternating ‘‘pin‐on‐plate’’ tribometer constructed as an ultrasonic motor with excited bimodal mechanical vibrations at the frequency of 20 kHz. Ultrasound sliding of the films was done against alumina ceramics and with the diamond film itself. We have shown that chemical vapor deposition diamond films can be fast polished mechanically without significant graphitization by ultrasonic treatment. The initial film roughness was reduced from an average Ra ≊3000 nm to Ra ≊10 nm. The polishing decreased the static coefficient of friction of the diamond film from about 0.53 to about 0.12. The operative mechanism for the polishing in the case of initially rough diamond samples appears to be asperity fracture. For smooth diamond samples it is suggested that tribochemical oxidation is also a polishing mechanism.