Synthesis, thermodynamic and magnetic properties of pure hexagonal close packed nickel

A novel and fast technique for the synthesis of pure hexagonal close packed (HCP) nickel is demonstrated. The HCP nickel was electrodeposited from NiCl2-1-ethyl-3-methylimidazolium chloride (NiCl2-EmimCl) ionic liquid at 160 °C. X-ray diffraction confirmed the formation of pure phase. A phase transformation from HCP nickel to face centered cubic (FCC) nickel was observed at 422.6 °C and the enthalpy of transformation was found to be 16.72 J g−1. The phase transformation resulted in the release of hydrogen which makes HCP nickel a potential hydrogen storage material. The electrodeposited nickel showed ferromagnetic properties and the magnetic coercivity was found to be 43 Oe.