Publications Details

Real space observations of magnesium hydride formation and decomposition

Herranz, T.; McCarty, K.F.; Santos, B.; Monti, M.; De La Figuera, J.

The growth and decomposition of thin layers of Mg and magnesium hydride on Ru(0001) using an in situ technique that provides real-space, real-time observations of the formation of hydride islands, was reported. The experiments have been performed using low energy electron microscopy (LEEM). Using LEEM, the growth of films was followed up to 10 atomic layers (AL) for temperatures between 300 and 430 K. With increased exposure time, there is little further nucleation. The LEED patterns of the 4 AL Mg film shows two sets of 6-fold diffraction spots, one set from the film and the other from the substrate. After being exposed to hydrogen the films were heated in UHV and the surface was simultaneously imaged by LEEM and gas generation monitored by temperature desorption (TD). In the LEEM images, no changes were observed up to temperatures around 450 K. From this temperature desorption of the Mg layers started. An increase in the decomposition temperature is observed with thicker original Mg films.