Nanocrystalline nickel and nickel-copper alloys: Synthesis, characterization, and thermal stability

Pulsed electrodeposition is a simple, yet versatile method for the production of nanostructured metals. Forn-nickel we determine the influence of the physical and chemical deposition parameters on the nanostructure of the deposits and demonstrate that the grain size can be tuned to values between 13 and 93 nm, with rather narrow grain size distribution. The thermal stability of ourn-nickel as studied by x-ray diffraction and differential thermal analysis exhibits no detectable grain growth up to temperatures of about 380 K and an initialbehavior at 503 K followed by a regime of anomalous grain growth. For nanocrystalline Ni_1-xCu_x(Monel-metal^™) we demonstrate that alloy formation occurs at room temperature and that both chemical composition and grain size can be controlled by the pulse parameters and by appropriate organic additives.