PHOTOELECTRON SPECTROSCOPY STUDY ON THE BONDING CHARACTERISTICS OF Mg, Mg2Ni, Mg2Cu AND THEIR HYDRIDES

摘要: Magnesium-based alloys are regarded as one kind of the most promising hydrogen storage materials. But they have two evident shortages: their hydrides too stable (working only at high temperatures) and poor hydriding dehydriding kinetics. In order to improve properties, fundamental studies urgently required. understand bonding characteristics magnesium-based hydrides, authors measured photoelectron spectra Mg, Mg2Ni, Mg2Cu hydrides. The Mg 2p electron binding energy is 49.5 eV for 53.8 MgH2, 49.4 Mg2Cu, 49.2 MgCu2, 50.1 Mg2NiH4. 2s changes in same pattern. These values show that a quite large transfer from atoms H occurs when hydrided Mg-H bonds rather ionic nature. formation intermetallicses Ni (or Cu), Ni(or Cu) atoms. Mg2NiH4 increase 2s) much smaller than forming there shows some energy, which may suggest well contribute electrons Mg2Ni hydrided, here not so MgH2. From results, micro-model proposed explain stability kinetics properties Mg-intermetallicses Mg2Cu.