Low temperature homogenization in nanocrystalline PdCu thin film system. (19th October 2015)

• Record Type: Journal Article
• Authors: Molnár, G Y; Katona, G L; Langer, G A; Csík, A; Chen, Y C; Beke, D L
• Is Part Of: Materials research express. Volume 2:Number 10(2015)
• Publication Date: 2015-10-19
• Subjects: diffusion -- solid-state reaction -- thin film -- SNMS depth profile; Materials science -- Research -- Periodicals; Materials science -- Periodicals; 620.11
• DOI: 10.1088/2053-1591/2/10/105012
• Languages: English
• ISSNs: 2053-1591

Abstract

Abstract: Diffusion and solid state reactions were investigated in Pd–Cu nanocrystalline films by means of secondary neutral mass spectrometry depth profiling technique. The heat treatments were made at low temperatures (where the volume diffusion was frozen in) for long enough annealing times to reach saturation. In the early stage there is a grain boundary interdiffusion. At longer times first a Pd plateau developed inside the Cu layer. Later on the Cu penetration was also more and more extended in the Pd, even the average composition of Cu in Pd became higher than the average Pd composition in Cu. Depending on the ratio of the initial thicknesses, the system (for thickness ratios corresponding to 50/50 Cu/Pd or to 75/25 Cu/Pd) arrived either at the mixture of pure Pd and β -CuPd phase or to the mixture of α ′-Cu3 Pd and β -CuPd phases, respectively, as dictated by the phase diagram. The process is interpreted as grain boundary diffusion induced solid state reaction.