Evidence of alloy formation in CoNi nanoparticles synthesized by nanosecond‐pulsed discharges in liquid nitrogen
Mahmoud Trad, Alexandre Nominé, C. Noël, Jaâfar Ghanbaja, M. Tabbal, Thierry Belmonte
Abstract
Abstract Producing alloy nanoparticles by discharge‐assisted erosion of electrodes immersed in liquid nitrogen is possible in the cobalt–nickel system. Several electrode configurations are tested. When one nickel electrode faces one cobalt electrode, Co x Ni 1− x alloy nanoparticles are produced with nickel cubic nanoparticles and cobalt round‐shaped faceted nanoparticles. The possibility of forming alloys is attributed to a sufficiently long residence time of both parent clusters within the discharge and to their total miscibility. It is also possible to form submicrometric Co x Ni 1− x alloy particles when discharges between cobalt electrodes are run in liquid nitrogen loaded with nickel nanoparticles produced in a former step. Starting by discharges between Co electrodes before Ni electrodes do not produce any alloy. The two mechanisms responsible for alloy synthesis are discussed.