Stability of Structure, Phase and Elemental Composition of Chemically Deposited and Electrodeposited Gold Layers in Multilayer Systems Auchemically reduced; electrodeposited /Co-W/Cusputtered / Glass-Ceramics

ABSTRACT

The changes in the structure and elemental composition of Au and Co-W thin layers after thermal treatment of 200 h at 200-300 ºC and 50 h at 450 ºC were systematically studied using the X-ray microanalysis of scanning electron microscope XL-30 ESEN Philips. The phase stability was evaluated by X-ray diffraction (XRD). The electrodeposited Co-W layer (W 46.0-53.0 wt. % depending on the electrodeposition regime) is amorphous and maintains its amorphous state after heating at 200 ºC for 200 h and subsequent heating (+) at 300 ºC for 150 h. Co-W amorphous layers prevent interdiffusion of Au and Cu atoms and formation of intermetallics AuCu in the systems of layers Au chemically reduced; Au electrodeposited /Co-W/Cu sputtered / glass-ceramics. The chemically reduced 0.4 􀀄m Au layers maintain their structure and phase in the systems of layers upon heating at 200 ºC for 200 h and subsequent heating (+) at 300 ºC for 50 h. The Au layer maintains its Au content 85-86 wt. % upon heating at 450 ºC for 50 h, the cobalt content of the layer up to 8.6 wt. % and content of oxygen bonded to Au of 8.6 wt. %. The electrodeposited Au layers (0.8 – 1.0 µm) maintain their structure at heating at 200 ºC and 300 ºC for 200 h. After additional heating at 450 ºC for 30-50 h gold content in the layer decreases from 98.4 wt. % to 85.0 wt. %, cobalt content increases to 7.6 wt. % and oxygen to 7.2 wt. %.

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