First principles study of ground-state properties of Laves phase ZrMn2 and its hydride

Abstract

The structural stability, elastic properties and bonding behavior of Laves phase ZrMn2 with C14, C15 and C36 structures as well as its hydride ZrMn2-H3 considering ferromagnetic (FM) ordering state were investigated by the first principles calculations. The calculated formation enthalpies and mechanical stability confirmed C14 structure is the stable crystal for ZrMn2 in FM ground state. A better hydrogen storage behavior of C14 phase ZrMn2 was predicted due to the obtained lower binding energy of hydrogen in ZrMn2-H3. In addition, there would be transformation of elastic behavior from ductility to brittleness, and increasing isotropy for ZrMn2 when H atoms are absorbed into 12k sites of crystal structure to form hydride ZrMn2-H3. The calculated density of states, charge density distributions and Mulliken populations revealed that additional hybridizations and covalent interaction between Zr and H atoms would be introduced with the absorption of H atoms in C14-phase ZrMn2.