Formation of supersaturated Au–Ni nanoparticles via dewetting of an Au/Ni bilayer

• The dewetting method is used to synthesize supersaturated Au–Ni solid-solution nanoparticles out of an Au/Ni bilayer thin film.
• Spherical nanoparticles inherit (111) texture from as-deposited bilayer and possess paramagnetic behavior.
• Dewetting of metallic bilayer films is shown to have great potential for fabrication of nanoalloys with tunable properties.

Supersaturated Au–Ni solid-solution nanoparticles are formed via dewetting of a nanometer Au/Ni thin bilayer using rapid thermal treatment. Annealing at temperatures well below the melting temperatures but above the miscibility gap induces the dewetting and involves the formation of Au–Ni solid-solutions. When cooling down to room temperature, particles formed are usually expected to decompose. When this is kinetically hindered, the supersaturated solution remains in dewetted state. These supersaturated particles are found to lose the ferromagnetic properties of Ni.

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