Regular Article

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

¹ School of Materials Science and Engineering, Shenyang Aerospace University, Shenyang 110136, Liaoning, PR China
² School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, Heilongjiang, PR China

^* e-mail: nzsfir@163.com

Received: 31 January 2018
Received in final form: 4 August 2018
Accepted: 10 October 2018
Published online: 16 November 2018

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.