Proton Irradiation and Hydrogen Diffusion in Quasicrystals

Abstract
Ti-Zr-Ni quasicrystals are new candidates for hydrogen storageapplications due to their capability of loading a large amount ofhydrogen at reasonable temperature and hydrogen pressure. Thetechnical applications, however, have been limited because of thepresence of a thick oxygen layer, which must be eliminated prior tointroducing hydrogen into a sample. To effectively remove the oxygenbarrier and to enhance the capability of hydrogen absorption, weirradiated Ti$_{39.5}$Zr$_{39.5}$Ni$_{21}$ quasicrystal ingots byusing a proton beam at energy of 20 MeV, 15 mA for 30 minutes. Theproton-beam-treated samples were exposed to a hydrogen pressure of650 psi at 200 $^circ$C and the results were analyzed by monitoringthe pressure change of the chamber. The main concerns were a carefulmeasurement of the weight gain after hydrogenation and an estimateof the peak shifts in X-ray diffraction. An absorption of hydrogenwas observed for the proton-beam-irradiated samples while littlehydrogen loading was noticed for unirradiated ones. Our resultsdemonstrate that proton irradiation may be used as a new techniquethat can effectively eliminate the oxygen barrier and enhance therates of hydrogen diffusion. However, more systematic investigationsregarding the role of the proton are required before applying thetechnique for practical applications.
Keywords: Proton beam, Quasicrystal, Hydrogen storage

 Search for

Indexed/Covered by