Size effect on excess resistivity induced by hydrogen in ultra-thin vanadium systems.

Through combining a four-point probe and an optical technique, a profound vanadium(v) size effect on the change in excess resistivity during hydrogenation is observed in Fen/V7n (n = 2, 4) superlattices at c ≥ 0.05 H/V. This phenomenon highly emphasizes the effect of interface and H-H interaction on the electrical properties of hydrogen in these systems.

Experimental observation of hysteresis in a coherent metal-hydride phase transition.

We investigate the hysteresis obtained in the hydrogen absorption and desorption cycle for a single crystal [Formula: see text] superlattice. Below the critical temperature, a small but clear hysteresis is observed in the pressure-composition isotherms, while it is absent above. The experimental results thereby prove the relevance of macroscopic energy barriers for obtaining hysteresis in coherent structural transformations.