Niobium single crystals are used as substrate material for constructing superconducting quantum interference device or SQUID. The use of niobium is prompted by the fact that it is a low Tc metallic superconductor. In order to fabricate the device the surface of the crystal has to be polished flat. This is achieved by combination of mechanical polishing and electrochemical polishing. It has been reported that during electrochemical polishing hydrogen can enter the material forming Niobium hydrides. These can result in surface roughening of a magnitude greater than the thickness of the films subsequently deposited. This leads to failure of the films. The problem can be solved by annealing the material at 300° C to remove any hydrogen that might be present. However it is phenomenologically interesting to study the effect of electrochemical hydrogen charging on the surface of Niobium.
|Name||Materials Research Society symposium proceedings|
|Publisher||Materials Research Society|
|Conference||Hydrogen in Semiconductors and Metals 1998|
|Period||13/04/98 → 14/04/98|