Fig. 1
From: Metal-hydrogen systems with an exceptionally large and tunable thermodynamic destabilization
The effect of Zr on the hydrogenation pressure of Y. a Schematic picture of the Y–Zr compositional gradient resulting in a wedge geometry with a thickness ranging from ~38 to 80 nm on a 70 × 5 cm quartz substrate, topped by a 5 nm Ti and 30 nm Pd cap layer. b Pressure transmission isotherms (PTIs) during the first hydrogen absorption cycle (0–40 mbar H2 at 25 °C). It shows the PTIs of 73 different Zr concentrations measured simultaneously in the thin film compositional gradient. Clearly, the pressure at which the YH2.1 → YH3 transition occurs depends on the Zr concentration. Each line in the graph represents a 0.015 at.% increase in Zr, starting from 1.5% Zr, i.e., Y98.5Zr1.5. c PTIs of the sample during the sixth hydrogen absorption cycle at 25 °C, starting from the dihydride state. d Desorption isotherm (PTIs) at 220 °C for selected Zr concentrations (Y96.6Zr3.4–Y85.5Zr14.5). Each isotherm represents a 0.38 at. % increase in Zr, starting from 3.5% Zr. Note that before dehydrogenation, the sample was first exposed to 104 mbar (10 bar) H2. The steps in pressure are due to due to the logarithmic decrease in hydrogen pressure from 104 to 1 mbar
