Deuterium storage of Ti40Zr40Ni20 icosahedral quasicrystal

Abstract

Ti 40 Zr 40 Ni 20 icosashedral quasicrystal was observed to load hydrogen in a much lower capacity than similar Ti–Zr–Ni alloys. To verify the result, the alloy is further studied by using deuterium instead of hydrogen in this work. With a home-made gas–solid reaction system, XRD and XPS techniques, the investigation was conducted on deuterium absorption and desorption properties of Ti 40 Zr 40 Ni 20 alloy and its phase stability during the deuteration course. It is shown that the quasicrystal can load deuterium rapidly in an elevated volume of 11.5 mmol·D 2 /g·M (D 2 denotes deuterium molecular and M the metal). After the full storage of deuterium, the quasicrystal phase remained, however the quasilattice expanded at a rate of 6.28%, revealing the occurrence of severe quasilattice stress. The solution of deuterium in the alloy caused the increase of binding energy of the metal elements, as much as 0.4 eV for Ti, 0.6 eV for Zr and 0.1 eV for Ni, which reflects the location of deuterium near Ti and Zr. The deuterium release was very slow at low temperature and could be complete at least above 610 °C. Based on the gained results, the quasilattice shrink would be more reasonable to explain the big difficulty of the desorption. ► Storage ability of 11.5 mmol·D 2 /g·M is discovered for Ti 40 Zr 40 Ni 20 quasicrystal. ► No phase change is observed during the deuteration of the quasicrystal. ► A 3D graph newly used visualizes how difficult D desorption of quasicrystal is. ► H site in Ti–Zr–Ni quasicrystal is confirmed by compelling XPS evidence.