Structure relaxation and crystallization of the CoW-CoNiW-NiW electrodeposited alloys
1 Far Eastern Federal University, Shukhanova 8, Vladivostok 690950, Russia
2 Scientific and Practical Centre of Material Science, Belarus National Academy of Sciences, P. Brovki 19, Minsk 220072, Belarus
Nanoscale Research Letters 2014, 9:66 doi:10.1186/1556-276X-9-66Published: 10 February 2014
The structure of electrolytically deposited nanocrystalline alloys of the CoW-CoNiW-NiW systems under low-temperature heating was investigated by means of high-resolution transmission electron microscopy (HRTEM), high-angle annular dark-field scanning transmission electron microscopy (HAADF STEM), and analytical methods such as energy dispersive x-ray spectroscopy (EDS) and electron energy loss spectroscopy (EELS). Structural relaxation and crystallization were investigated at temperatures of 200°C to 300°C. The structural and compositional inhomogeneities were found in the CoW-CoNiW-NiW alloys, while the local changes in composition were found to reach 18 at.%. Nanocrystals in the alloys grew most intensely in the presence of a free surface, and we found their nuclei density to range from 2 × 1023 /m3 to 3 × 1023 /m3. It was determined that the local diffusion coefficient ranged from 0.9 to 1.7 10−18 m2/s, which could be explained by the prevalence of surface diffusion. The data gathered in these investigations can be used to predict the thermal stability of CoW-CoNiW-NiW alloys.