Author, Institution: Hassan Zhairabany, Kaunas University of Technology
Science area, field of science: Technological Sciences, Materials Engineering, T008
Research supervisor: Prof. Dr. Liutauras Marcinauskas (Kaunas University of Technology, Natural Sciences, Physics, N002)
Research consultant: Senior Researcher Dr. Algirdas Lazauskas (Kaunas University of Technology, Technological Sciences, Materials Engineering, T008)
Dissertation Defence Board of Materials Engineering Science Field:
Prof. Dr. Hab. Arvaidas Galdikas (Kaunas University of Technology, Technological Sciences, Materials Engineering, T008) – chairperson
Prof. Dr. Justinas Čeponkus (Vilnius University, Natural Sciences, Physics, N002)
Chief Researcher Dr. Šarūnas Meškinis (Kaunas University of Technology, Technological Sciences, Materials Engineering, T008)
Assoc. Prof. Dr. Pavels Onufrijevs (Riga Technical University, Latvia, Technological Sciences, Materials Engineering, T008)
Prof. Dr. Tomas Tamulevičius (Kaunas University of Technology, Technological Sciences, Materials Engineering, T008)
Dissertation defence meeting will be at Rectorate Hall of Kaunas University of Technology (K. Donelaičio 73-402, Kaunas)
The doctoral dissertation is available at the library of Kaunas University of Technology (Gedimino 50, Kaunas) and on the internet: H. Zhairabany el. dissertation.pdf
© H. Zhairabany, 2026 “The text of the thesis may not be copied, distributed, published, made public, including by making it publicly available on computer networks (Internet), reproduced in any form or by any means, including, but not limited to, electronic, mechanical or other means. Pursuant to Article 25(1) of the Law on Copyright and Related Rights of the Republic of Lithuania, a person with a disability who has difficulties in reading a document of a thesis published on the Internet, and insofar as this is justified by a particular disability, shall request that the document be made available in an alternative form by e-mail to doktorantura@ktu.lt.”
Annotation: Diamond-like carbon (DLC) films are widely used in various industrial fields from biomedicine, microelectronics to automotive due to their low friction coefficient, high wear resistance and chemical inertness. By controlling the concentration of the doped metals or by co-doping with several metals, it is possible not only to control the structure of diamond-like carbon coatings, but also to manage the mechanical and tribological properties. However, there is still a lack of research on the dependence of the structure, nanomechanical, and especially nanotribological properties of doped DLC films on the metals dopants concentrations and the synthesis temperature. This dissertation presents a systematic study of the mechanical and nanotribological properties of molybdenum and chromium/nickel doped diamond-like carbon films. The variation of the microstructure, elemental composition, mechanical and nanotribological properties of Mo-DLC films as a function of molybdenum concentration and synthesis temperature was evaluated. The doping of DLC films with Mo reduces the friction coefficient by 25% without decreasing the nanohardness of the films. For the first time, the chromium/nickel co-doped DLC films were deposited by magnetron sputtering and the dependence of films structure and nanotribological properties on the Cr/Ni concentration and synthesis temperature was studied. With the appropriate selection of Cr/Ni concentration and deposition conditions, the friction coefficient of DLC films is reduced by 35%, and the nanohardness is increased by 40%. The studies conducted show that the Mo-DLC and Cr/Ni-DLC films could be used in micro- and nano-electromechanical systems as protective and friction-reducing layers.