Low-temperature hydrogen absorption into V and Nb metals from liquid hydrogen

We report experimental study on low-temperature hydrogen (H) absorption in vanadium (V) and niobium (Nb) nanocontacts below T= 20 K using a point-contact spectroscopy (PCS) technique. When a small bias voltage is applied between both sides of nanocontacts immersed in liquid H-2, the differential conductance (dI/dV) and the second derivative (d(2)I/dV(2)) are changed from those for pure V and Nb nanocontacts. Further, the spectra approach to those for a high concentrated phase of H with increasing the bias voltage. The results indicate that in-situ investigation of H absorption process from liquid H-2 is possible through dI/dV and d(2)I/dV(2) measurements using the PCS technique.