Formation of nanofibers in thin layers of amorphous W alloys with Ni, Co, and Fe obtained by electrodeposition

Scanning tunneling microscopy (STM) experiments supported by scanning electron microscopy (SEM) pictures and X-ray diffractometry indicate that all electrodeposited amorphous alloys of tungsten with the iron-group metals are in fact of nanofibrous structure. It has been shown that the nanofibers grow perpendicularly to the copper support and, as the thickness of the alloy microlayer grows, group into well-packed bundles. The thickness of the fibers, for 79: 21 Ni-W and 75: 25 Co-W determined from the STM images, equals 50 Angstrom. This number correlates well with the average grain size (40-55 Angstrom) calculated, using the Scherrer formula, from the peak broadening seen at the X-ray spectrograms. (C) 2003 The Electrochemical Society.