Magnetic measurements of hydrogen desorption from palladium hydride PdH0.64 prepared by severe plastic deformation

Hydrogen absorption and desorption through diffusive processes and the accompanying phase transformations in hydrogen storage materials have been investigated by x-ray diffraction, thermogravimetry, pressure-composition-temperature isotherms, and electrical resistance measurements. We use time- and temperature-dependent magnetic measurements to gain a detailed understanding of these phenomena in palladium hydride PdH 0.64 prepared by severe plastic deformation via the high-pressure torsion method. The concept of our method is pursuing an increase in the ratio of the paramagnetic alpha -phase Pd+H to the diamagnetic beta -phase PdH. An antiferromagnetic correlation appears between the paramagnetic moments of Pd at a low temperature and a huge discrete change in magnetization appears due to collective H desorption above room temperature. It is also verified that H diffusion and its desorption can be changed with the accumulation of the severe lattice strain.