Capacitance distribution of Ni-Nb-Zr-H glassy alloys

Capacitance distribution of {(Ni _0.6Nb _0.4) _1-xZr _x} _100-y-H _y (x = 0.30, 0.35, 0.40, 0.45 and 0.50, 0 ≥ y ≥ 20) glassy alloy ribbons was carried out by ac impedance analysis at frequency of 1 kHz, in terms of a distributed constant equivalent circuit. The capacitance can be represented by oblique contour lines. The highest capacitance (1-11 μF) could be found near the point when x = 0.40, y = 10, which is a composition occurring room-temperature Coulomb oscillation, while capacitance of the composition (x =0.35, y =4) occurring ballistic transport was around 0.8 μF. The capacitance difference would be explained by an effect of hydrogen localization derived from morphology of distorted Zr-centered icosahedral Zr ₅Ni ₅Nb ₃ clusters and ideal Ni-centered clusters. The electrocapillarity equation showed that the specific capacitance between two electrodes increases parabolic with decreasing the distance, as a polarized glutinous liquid.