AlMgB14-Based Films Prepared by Magnetron Sputtering at Various Substrate Temperatures

The films were deposited by magnetron sputtering the AlMgB14 target at different substrate temperatures (TS) in the range of 100-500 C. The films were annealed at 1000 C in vacuum. The deposited films were characterized by XRD, AFM, FTIR spectroscopy, nano- and micro-indentation and scratch testing. The films exhibit hardness that is much lower than the one of the bulk AlMgB14 materials, which is due to the amorphous film structure in which the strong B-B bonds are absent and the weaker B-O bonds dominate

Nanocomposites TiN – TiB2, TiN – Si3N4 Consolidated by Electric Discharge Technology

Investigation of consolidation process by electric discharge sintering (EDS) at the temperatures 1400 – 1550 °C for nanostructured high melting point powders and composition are described in the paper. In the present work we apply EDS technology to consolidate nanocomposites in the system TiN – TiB2, TiN – Si3N4. Influence of green body form and conductivity of the nanopowders on the densification process and mechanical properties of sintered bodies are studied. Sintering experiments were carried out in CO atmosphere When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3507

Characterization of Ti-B-C-N Nanocomposite Coatings

Nanocomposite Ti-B-N-C coatings were deposited by magnetron sputtering of TiN and B4C targets in the argon-nitrogen atmosphere at different nitrogen flow rates (FN2). The structure, chemical bonding and mechanical properties were investigated. The results of the investigations of the nanocomposite, TiN and BCN coatings show that the Ti-B-C-N coatings consist of the TiNC nanocrystals (3.4 – 6.5 nm) embedded into the amorphous matrix that consists of amorphous boron nitrogen (a-BN) and amorphous carbon (a-C). The coatings contain a small admixture of titanium oxides that are aggregated at the grain boundaries. The coatings deposited at high nitrogen flow rates were textured. An introduction of nitrogen prompts the formation of the nanocrystallites of the TiN-TiC solid solutions and the a-BN amorphous tissue, which, in turn, causes the improvement of the mechanical properties of the Ti-B-C-N coatings. The best samples ex-hibited nanohardnes above 39 GPa. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3505

Comparative investigation of NbN and Nb–Si–N films: experiment and theory

NbN and Nb–Si–N films have been deposited by magnetron sputtering of the Nb and Si targets on silicon wafers at various powers supplied to the Nb target. The films have been investigated by an atomic force microscope, X-ray diffraction, X-ray photoelectron spectroscopy, nanoindentaion and microindentation. The NbN films were nanostructured, and the Nb–Si–N films represented an aggregation of δ-NbNx nanocrystallites embedded into the amorphous CSi₃N₄ matrix (nc-δ-NbNx/a-CSi₃N₄). The annealing of the films in vacuum showed that their intensive oxidation occurred at annealing temperature higher than 600 °C. To explain the experimental results on the Nb–Si–N films, first-principles molecular dynamics simulations of the NbN(001)/CSi₃N₄ heterostructures have been carried out.NbN і Nb–Si–N плівки осаджували на кремнієві пластини методом магнетронного розпилення мішеней Nb і Si при різних потужностях розряду на мішені із Nb. Плівки були досліджені за допомогою атомно-силового мікроскопа, дифракції рентгенівських променів, рентгенівської фотоелектронної спектроскопії, нано- і мікроіндентування. NbN плівки були наноструктуровані, тоді як Nb–Si–N плівки являли агрегацію δ-NbNx нанокристалітів, вкраплених в аморфну CSi₃N₄ матрицю (nc-δ-NbNx/ a-CSi₃N₄). Відпал плівок у вакуумі показав, що їх інтенсивне окислення відбувається при температурі вищій, ніж 600 °C. Для пояснення експериментальних результатів по Nb–Si–N плівках проведено моделювання NbN (001)/CSi₃N₄ гетероструктури із перших принципів в рамках молекулярної динаміки.NbN и Nb–Si–N пленки осаждали на кремниевые пластины методом магнетронного распыления мишеней Nb и Si при различных мощностях разряда на мишени с Nb. Пленки были исследованы с помощью атомно-силового микроскопа, дифракции рентгеновских лучей, рентгеновской фотоэлектронной спектроскопии, нано- и микроиндентирования. NbN пленки были наноструктурированные, тогда как Nb–Si–N пленки представляли агрегацию δ-NbNx нанокристаллитов, вкрапленных в аморфную CSi₃N₄ матрицу (nc-δ-NbNx/a-CSi₃N₄). Отжиг пленок в вакууме показал, что их интенсивное окисление происходит при температуре выше, чем 600 °C. Для объяснения экспериментальных результатов по Nb–Si–N пленках проведено моделирование NbN (001)/CSi₃N₄ гетероструктуры из первых принципов в рамках молекулярной динамики.This work was partially supported by STCU Contract No. 5539. The authors are grateful to Dr. Timofejeva, I. I. and Dr. Dub, S. N. for XRD investigations and nanoindentation of the films. The authors are grateful to the directorate of the Summery Institute at Jackson State University for financial support and the possibility to perform large-scale calculations

AlMgB14-Based Films Prepared by Magnetron Sputtering at Various Substrate Temperatures

The films were deposited by magnetron sputtering the AlMgB14 target at different substrate temperatures (TS) in the range of 100-500 C. The films were annealed at 1000 C in vacuum. The deposited films were characterized by XRD, AFM, FTIR spectroscopy, nano- and micro-indentation and scratch testing. The films exhibit hardness that is much lower than the one of the bulk AlMgB14 materials, which is due to the amorphous film structure in which the strong B-B bonds are absent and the weaker B-O bonds dominate