Kolomiyets O. The effect of pressure and hydrogenation on the magnetic properties of the f-electron compounds

The Thesis is focused on solving the scientific and applied problem of the influence of the structural changes due to the hydrogenation and the external compression on the physical properties of the f-electron compounds. The influence on the crystal structure, magnetic, transport and thermodynamic properties of both methods of the lattice modification has been studied. It has been shown that the hydrogenation could be used as the effective ‘negative’ pressure agent, which is complementary to the external pressure, thus doubling the range, in which the interatomic distances could be varied during the studies of the f-electron compounds without the necessity to alloy them and without the loss of the crystallinity. The compounds with the 4f- and 5f-electron elements, that is with the rare earths and uranium, have been studied within the unified framework focused on the interatomic distances and their effect on the electronic structure. It has been shown that in the hydrides of the f-electron compounds the role of the metal-hydrogen bonding is secondary.