Hydrogen Distribution in Partly Desorbed MgH2 Samples

Abstract

The structure of MgH2 samples has been investigated by the neutron diffraction method at room temperature and 5 K. Samples of MgH2 have been prepared with vacuum extraction technique at high temperature. Obtained neutron data demonstrated that samples contain coexisting Mg and MgH2 phases in different rate. The distribution of hydrogen atoms in the structure of the samples is comparable at both temperatures. Collected neutron data and results of X-ray analysis show that microstructure of the samples is different at room and at low temperature. Non-stability of partly desorbed MgH2 samples after low temperature treatment has been discussed on basis of different diffusion of hydrogen atoms in varied microstructure.