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Information × Registration Number 0212U006858, 0110U005740 , R & D reports Title Development of basic physics of CVD process of nitrogen doped conductive nanocrystalline diamond materials synthesis popup.stage_title Head Strel'nitskij Vladimir Evgenievich, Доктор фізико-математичних наук Registration Date 19-07-2012 Organization National Science Center "Kharkiv Institute of Physics and Technology popup.description2 The scientific-research report: 46 p., 18 Fig., 3 tab., 20 references. Subject of investigation is the method of CVD nitrogen doped nanostructural diamond coatings synthesis. The purpose of stage is investigation the influence of nitrogen concentration in the gas mixture on the kinetics of formation and structure of diamond films synthesized in a glow discharge plasma. The method of study is an experimental investigation of the influence of the diamond coatings parameters synthesis on their growth rate and structure using the gravimetric method, a method of scanning electron microscopy and X-ray diffraction. Study of influence of the gas phase composed of mixture of CH4 and H2 with addition of Ar and N2 on kinetics of formation and structure of diamond thin coatings deposited in a glow discharge plasma was performed. It was found that the growth rate of nanostructural diamond coatings with increasing nitrogen concentration in the range of 6-38% due to a corresponding decrease in the hydrogen concentration increases approximately linearly. Increasing the concentration of argon in the gas mixture through a corresponding reduction of hydrogen concentration leads to a decrease in the growth rate of diamond coatings. The activation energy for the diamond films growth in the temperature range studied 820 -960 ?C and composition of gas mixture (60% Ar, 19% N2, 2,1% CH4, the rest - hydrogen) is of the order of 26 kcal/mol for temperatures below 900 ?C, while at higher temperatures the activation energy is about 11 kcal/mol. X-ray analysis in combination with electron microscopy studies showed that with increasing of nitrogen concentration changes in the structure and size of structural elements of the diamond films occurs non-monotonically. Feeding of nitrogen to the gas mixture in the range (6-20)% leads to a shift formation of the nanocrystalline structure of diamond films in the direction of greater methane concentration and increase the size of coherent regions from 20 to 25 nm. With further increase concentration of nitrogen structural elements are decreased, take an elongated needle-like shape, and the average coherent region dimensions is reduced to 10 nm. Volume content of diamond phase in all films determined by X-ray analysis is not significantly different. The value of the crystal lattice of diamond films is in the range (0,3545-0,3557) nm, which is somewhat below the tabular values for natural diamond (a = 0.3567 nm). During deposition formed textured films with preferred orientation of diamond crystallites along <110> direction normal to the substrate surface. Increasing of argon concentration in the gas mixture leads to a reducing of diamond film crystallites, to a more defective structure and enhance the texture. Studies have shown that deposition of diamond coatings in a glow discharge plasma in the case of nitrogen feeding into the gas phase retains an inherent feature of this method to lower the concentration of argon necessary for the formation of nanostructural diamond films. This allowed us to study the influence of nitrogen concentration on the formation of nanostructural diamond films in a wide range of its changes not at the expense of reducing the concentration of argon, as in most other studies, and by reducing the amount of hydrogen. The results of these studies indicate that nitrogen and hydrogen can be competitive in the processes responsible for the diamond coating growth rate and the formation of nanostructures. Prognoses estimation concerning evolution of investigation subject is the development of physical principles of process of the electroconductive nanostructural nitrogen doped diamond coatings synthesis. Product Description popup.authors Бородін Олег Вікторович Василенко Руслан Леонідович Воєводін Віктор Миколайович Волков Юрій Якович Грицина Василь Васильович Дудник Станіслав Федорович Залеський Дмитро Юрійович Комар Анатолій Анатолійович Кошевий Костянтин Іванович Луценко Валентин Дмітрович Опалев Олег Анатолійович Перепьолкін Сергій Степанович Решетняк Олена Миколаївна Стрельницький Володимир Євгенійович popup.nrat_date 2020-04-02 Close