Assessment of changes in desorption mechanism of MgH2 after ion bombardment induced destabilization

This paper deals with non-isothermal kinetics models of hydrogen desorption from MgH2 altered by ion bombardment and stresses the importance of the MgH2 surface during its decomposition. In the case of argon-irradiated samples, where defects are induced in the near-surface region, the Avrami Erofeev mechanism with parameter n = 2 can be adopted while in the case of boron-irradiated samples, where defects are created deeper in the bulk, the desorption mechanism is the same with n = 3. The difference is possibly related to the concentration and good dispersion of defects in near-surface region in the samples.

► Ion irradiation is good method to control the deposited energy and defects amount.
► The defects distribution is controllable using ion irradiation.
► Importance of concentration and defects’ distribution in subsurface area is shown.
► Increased defects’ concentration in subsurface area changes H desorption mechanism.
► Defects’ distribution throughout the material also affect the desorption mechanism.