Investigation of the interplay of nickel dissolution and copper segregation in Ni/Cu(111) system

Interdiffusion at Room Temperature in Cu-Ni(Fe) Nanolaminates

“…The ratio between the normalized satellite and Bragg peaks is compared between the as-deposited condition, and after 30 years aging at room temperature. An initial nonlinear response [19,22] in the ln-scale, normalized-satellite intensity variation with anneal time, i.e., amplification factor R, that can occur from a strong composition dependence in Cu-Ni [27,28] is not anticipated in this study since the growth of the final wavelength λ (nm) initial wavelength λ (nm) Figure 1. The θ/2θ X-ray diffraction scans shows the satellite peaks below (−1) the (111) Bragg reflections of the Cu-Ni(Fe) nanolaminates with composition wavelengths of 3.04 nm (green curve) and 3.15 nm (blue curve) and the (Cu) base layer for epitaxial growth.…”

“…The ratio between the normalized satellite and Bragg peaks is compared between the as-deposited condition, and after 30 years aging at room temperature. An initial nonlinear response [19,22] in the ln-scale, normalized-satellite intensity variation with anneal time, i.e., amplification factor R, that can occur from a strong composition dependence in Cu-Ni [27,28] is not anticipated in this study since the growth of the composition fluctuation at room temperature is measured using nanolaminates that had initially undergone significant homogenization [19] at temperatures outside the spinodal to greatly reduce the amplitude of the composition profile to a small fluctuation-a necessary condition for the diffusion model. The variation of the amplification factor R with the dispersion relation B of the Cu-Ni(Fe) structure is plotted in Figure 3.…”

Linear growth kinetics of nanometric silicides in Co/amorphous-Si and Co/CoSi/amorphous-Si thin films

“…3,4 Several papers have been published recently studying interface shift [5][6][7] and/or interface sharpening 8 in binary ideal solid solutions 5 and in phase separating systems 6,7 as well. These studies suggest that linear interface shift may occur due to large diffusion asymmetry ͑large difference in the diffusion coefficients of the materials in contact͒ even if there is no extra potential barrier present accounting for an interface reaction control.…”

“…The earlier evidences show that such nonparabolic kinetics can occur on the nanoscale at the early stage of diffusion process, which later on, for longer diffusion distances turns back to the usual Fick type, parabolic growth law. [5][6][7] Then it is a plausible question whether linear kinetics can similarly be observed during solid state reactions with growth of an ordered phase.…”

Interface Sharpening instead of Broadening by Diffusion in Ideal Binary Alloys

“…Furthermore, it is also shown that at the beginning of the intermixing in a finite bilayer or in multilayers, the diminution of the concentration gradient takes place by filling up one of the initially pure layers (layer B if D is large there) and by the shift of the sharpening interface. DOI: 10.1103/PhysRevLett.89.165901 PACS numbers: 66.30.Pa, 68.35.Fx Very recently, studying the dissolution of thin (3 and 8 monolayers thick) Ni films into Cu(111) substrate, it was shown (both by experiments and by computer simulations, based on deterministic kinetic equations) that the interface remains sharp and shifts proportionally with the time t (in contrast to a shift with t p ) even in ideal systems having complete mutual solubility [1]. This result is inherently related to the strong nonlinearity of the problem: the strong concentration dependence of the diffusion coefficient D shifts the validity limit of the continuum approach (see also [2]), from which a parabolic law would be expected, out of the nanometer range.…”