Hydrogen-induced phase transition of MgZrTiFe0.5Co0.5Ni0.5 high entropy alloy

• DOI: 10.1016/j.ijhydene.2017.11.106
• Publication Date: 2017-12-07T16:35:00Z
• Authors: G. Zepon; D.R. Leiva; R.B. Strozi; A. Bedoch; S.J.A. Figueroa; T.T. Ishikawa; W.J. Botta
• Keywords: 01 natural sciences; 0104 chemical sciences

Abstract In this study, the MgZrTiFe0.5Co0.5Ni0.5 high entropy alloy was processed by high-energy ball milling under both argon and hydrogen atmospheres. The hydrogen storage behavior of the samples was evaluated by combination of thermal analyses and in-situ synchrotron powder X-ray diffraction. It is shown that this alloy forms a body-centered cubic (BCC) structure when milled under argon pressure. The BCC phase is capable to absorb up to 1.2%wt. of hydrogen and during absorption it undergoes a phase transition forming a face-centered cubic (FCC) high entropy hydride. This FCC hydride can be directly synthesized by high-energy ball milling under hydrogen pressure.