Correction: Corrosion and tribocorrosion performance of multilayer diamond-like carbon film in NaCl solution

Correction for ‘Corrosion and tribocorrosion performance of multilayer diamond-like carbon film in NaCl solution’ by Mingjun Cui et al., RSC Adv., 2015, 5, 104829–104840, DOI: 10.1039/C5RA21207C.

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.

FIELD DESORPTION MICROSCOPY OF CARBON-COATED FIELD ELECTRON EMITTERS

Полевые электронные эмиттеры в форме металлического острия с пленкой углерода на поверхности обладают рядом перспективных эксплуатационных свойств. Характеристики эмиттера зависят от фазового состава, толщины и однородности пленки. Определение параметров пленок толщиной в один или несколько моноатомных слоев представляет определённые трудности. В данной работе образование и характеристики углеродных наноструктур на поверхности полевых эмиттеров из иридия и рения исследуются с помощью полевой десорбционной микроскопии непрерывного режима. На полевых десорбционных изображениях области углеродных наноструктур проявляются в виде локальных вспышек (лавинообразная десорбция). При покадровом анализе видеозаписей вспышек обнаружено несколько стадий формирования вспышек и выявлены различия в протекании десорбции с углеродных наноструктур на иридии и на рении. Обнаруженные различия объясняются образованием на иридии однослойного, а на рении многослойного графена. Десорбционные изображения выявляют неоднородности и локальные различия толщины пленки. Показано, что полевая десорбционная микроскопия непрерывного режима позволяет определять закономерности формирования полевых десорбционных изображений различных углеродных наноструктур, в частности, однослойного и многослойного графена на поверхности полевого эмиттера, и проводить диагностику поверхности после науглероживания и контролировать однородность получаемого покрытия. Получаемые данные полезны для разработки технологии эффективных полевых электронных эмиттеров. Field electron emitters in the form of a metal tip with a carbon film on the surface have a number of promising operational properties. The characteristics of the emitter depend on the phase composition, thickness and uniformity of the film. Determining the parameters of films with a thickness of one or more monoatomic layers presents certain difficulties. In this paper, the formation and characteristics of carbon nanostructures on the surface of field emitters made of iridium and rhenium are studied using continuous-mode field desorption microscopy. In the field desorption images, the regions of carbon nanostructures appear as local flashes (avalanche-like desorption). Frame-by-frame analysis of flash video recordings revealed several stages of the flash formation and revealed differences in the desorption from carbon nanostructures on iridium and rhenium. The found differences are explained by formation of the single-layer graphene on iridium and a multilayer graphene on rhenium. Desorption images reveal inhomogeneities and local differences in the film thickness. It is shown that continuous-mode field desorption microscopy makes it possible to determine the regularities of formation of the field desorption images of various carbon nanostructures, in particular, the single-layer and multilayer graphene on the surface of the field emitter, and to diagnose the surface after carburization. Besides, control the uniformity of the resulting coating is possible. The obtained data are useful for developing technology of the effective field electronic emitters.

Investigation of the Chemical Composition of Films Obtained by Electric Arc Spraying of Graphite and Titanium from Two Sources

A promising material for cold cathodes creation are carbon films with both acceptable emission properties and satisfactory adhesion to the substrate. It is known that inclusions of metallic elements (chromium, titanium, etc.) improve the adhesion of the carbon film to the substrate. One of the methods for producing coatings based on carbon and titanium is electric arc spraying of a Ti/C composite cathode in an argon atmosphere. The disadvantage of this method is the presence in the total plasma flow of carbon microparticles, which are sources of structural defects in the growing film. Magnetic separation of carbon plasma solves the above problem. In this work, composite metal-carbon films were obtained by simultaneous electric arc spraying of graphite in a magnetic field and of titanium from two evaporators. The composition of the films was studied by Raman spectroscopy (RS) and X-ray photoelectron spectroscopy (XPS). It has been established that the samples obtained are composite films consisting of graphite nanoparticles, Ti14C13 nanoclusters or Ti8C12, titanium oxides, and titanium carbide TiCxN1–x compounds.

Polyethylene glycol derived carbon quantum dots nanofluids: An excellent lubricant for diamond-like carbon film/bearing steel contact

Polyethylene glycol derived carbon quantum dots nanofluids were synthesized via a slow thermal oxidation process. The size of carbon quantum dots was ca. 2 nm and had a decreasing trend with the increase of oxidation time. When used as lubricant in a diamond-like carbon film/bearing steel interface, the nanofluids achieved an ultra-low friction coefficient (μ ≈ 0.02), much lower than that of original polyethylene glycol (μ = 0.12). The worn surface analyses revealed that the nanofluids could effectively inhibit the tribo-oxidation of steel counterpart that occurred under original polyethylene glycol lubrication, and hence reduced the abrasion component of friction. Especially, the poly-hydroxyl carbon dots and oxidized polyethylene glycol species in nanofluids induced a hydroxyl-rich sliding interface via their tribochemical reactions with friction surfaces, which promoted the adsorption of polyethylene glycol molecules on sliding surfaces. Along with the mild corrosion wear of steel counterface, this shifted the boundary lubrication to a mixed/film lubrication regime, thereby achieving an ultra-low friction coefficient. The above results suggest that the polyethylene glycol derived carbon quantum dots nanofluids should be a quite excellent candidate lubricant for solid-liquid synergy lubrication based on diamond-like carbon films.