Phase and structure stability of thin gold layers in the systems of various metal alloys and metallized ceramics

Full text: Phase and structure stability, changes in the atomic composition of chemically deposited (thickness 0.3-0.6 μm) and electrodeposited (thickness 0.8-1.8 μm) Au layers and electrodeposited (thickness 1-2 μm) X-ray amorphous Co-50 wt.% W and Co-36 wt.% Mo alloy layers in the following systems Au/Co-W/Cu/glass-ceramics, Au/Co-W/Fe- Ni(Ni80)/glass-ceramics, Au/Co-W/Ti foil, Au/Co-W/Fe-Ni(Ni40) and Au/Co-Mo/Cu foil were investigated after their heating at 2000C for 200 h [1], at 3000C for 100-150 h, at 450 and 4700C for 50 and 15 h, respectively, by scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDAX). The results of investigations demonstrate that the electrodeposition of the X-ray amorphous Co-W alloy ensures the stability of phase composition and adhesion of the Au layers. The inception of crystallization of the Co-W layer and the formation of a little Co3O4 and CoWO4 were observed after long time heating at 3000C for 100 h and 450-4700C for 10-15 h. The started investigations demonstrate that the Co-Mo layer maintains its X-ray amorphous state and the Au phase stability after the heating at 3000C for 50 h. Crystal growth was observed on the surface of thin chemically deposited Au layers (thickness 0.4 μm). That is determined by incomplete Au crystallization the chemical deposition. The Au crystallization continues at the heating. Si diffusion from the glass-ceramics and formation of Co-Si, Au-Si, Co-Ti and Au-Cu compounds were not observed at the above-mentioned temperatures. [1] I.Vitina, A.Knipele, V.Belmane, V.Rubene, I.Jansone, M.Lubane, M.Berzins. Abstracts. Of the 19th Scientific Conference, dedicated to 25 th anniversary of Institute of Solid State Physics UL, 44 (2003)