Electrochemical nanoindentation: A new approach to probe hydrogen/deformation interaction

The effect of hydrogen on dislocation nucleation is examined on Ni single crystals with (1 1 1) surface orientation with a specifically designed nanoindentation setup for in situ electrochemical experiments. This is the first time that hydrogen/deformation interaction has been studied in situ on a nanoscale under realistic conditions. The effect of the electrochemical potential on the indent load–displacement curve, especially the unstable elastic plastic transition (pop-in) is studied in detail. Clear evidence is provided that hydrogen atoms facilitate homogenous dislocation nucleation.