TY - JOUR

T1 - Arc discharge sputtering of NiO-C electrodes: Structure and magnetic properties of synthesized materials

AU - Zaikovsky, Alexey

AU - Leonov, Nikolay

AU - Ukhina, Arina

N1 - The authors acknowledge CCU VTAN NSU for caring out of transmission electron microscopy. The authors also acknowledge Kutateladze Institute of Thermophysics for the usage of the unique scientific equipment “Vacuum Gasdynamic Complex” for arc discharge synthesis of the materials.

PY - 2023/12

Y1 - 2023/12

N2 - Plasma-chemical processes occurring during arc discharge sputtering of electrodes consisting of graphite and nickel oxide lead to the formation of a composite nanomaterial containing core–shell Ni@C nanoparticles. The structure of the formed material depends on the initial pressure in the reactor chamber. The smallest nickel nanoparticles with an average size of 3 nm are formed at a pressure of 12 Torr. The use of both lower 3 Torr and higher 100 Torr pressures results in the formation of larger nickel nanoparticles with average sizes of 5 and 9 nm, respectively. The proposed mechanism for the synthesis of Ni@C structures in the process of the arc discharge, including the stages of formation of a gas-plasma mixture, its outflow into the reactor chamber and cooling, processes of condensation, crystallization, and formation of nanoparticles, is considered. The structure of the material formed on a graphite substrate at various distances from the arc discharge axis was studied. It was established that larger nickel nanoparticles were formed at a closer distance, while the carbon component took the form of a graphene structure. With distance from the discharge, the size of the formed nickel nanoparticles decreased, and the graphene structure acquired a larger number of defects. Studies have showed that the synthesized materials, in terms of the mass content of nickel, had a specific magnetic susceptibility that exceeded the value for bulk metallic nickel. It was established that a decrease in the size of nickel nanoparticles led to an increase in the specific magnetic susceptibility of the material.

AB - Plasma-chemical processes occurring during arc discharge sputtering of electrodes consisting of graphite and nickel oxide lead to the formation of a composite nanomaterial containing core–shell Ni@C nanoparticles. The structure of the formed material depends on the initial pressure in the reactor chamber. The smallest nickel nanoparticles with an average size of 3 nm are formed at a pressure of 12 Torr. The use of both lower 3 Torr and higher 100 Torr pressures results in the formation of larger nickel nanoparticles with average sizes of 5 and 9 nm, respectively. The proposed mechanism for the synthesis of Ni@C structures in the process of the arc discharge, including the stages of formation of a gas-plasma mixture, its outflow into the reactor chamber and cooling, processes of condensation, crystallization, and formation of nanoparticles, is considered. The structure of the material formed on a graphite substrate at various distances from the arc discharge axis was studied. It was established that larger nickel nanoparticles were formed at a closer distance, while the carbon component took the form of a graphene structure. With distance from the discharge, the size of the formed nickel nanoparticles decreased, and the graphene structure acquired a larger number of defects. Studies have showed that the synthesized materials, in terms of the mass content of nickel, had a specific magnetic susceptibility that exceeded the value for bulk metallic nickel. It was established that a decrease in the size of nickel nanoparticles led to an increase in the specific magnetic susceptibility of the material.

KW - Arc discharge

KW - Biomedical relevance

KW - Core–shell nanoparticles

KW - Magnetic susceptibility

KW - Nickel nanoparticles

KW - Plasma

KW - Synthesis

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85178661926&origin=inward&txGid=d8c425f37be78ac1c8a57b4da6765226

UR - https://www.mendeley.com/catalogue/3a43818d-1913-3365-ab06-3b262ca312bd/

U2 - 10.1007/s11051-023-05907-y

DO - 10.1007/s11051-023-05907-y

M3 - Article

VL - 25

JO - Journal of Nanoparticle Research

JF - Journal of Nanoparticle Research

SN - 1388-0764

IS - 12

M1 - 252

ER -