Electrochemical Preparation of ZrFe₂ and ZrFe1.8Ni0.2 Intermetallic Compounds by FFC Cambridge Process

The aim of the present study was to prepare ZrFe 2 and ZrFe 1.8 Ni 0.2 intermetallic compounds by FFC Cambridge process. The intermetallic compounds were prepared directly from the mixed oxide precursors, namely ZrO 2 -Fe 2 O 3 and ZrO 2 -Fe 2 O 3 -NiO, respectively. Electrochemical de-oxidation experiments were carried out with mixed oxide pellet cathode and HD graphite anode by applying a constant cell voltage of 3.1 V in CaCl 2 melt at 900 o C. The electrochemical behaviour of oxides was studied by cyclic voltammetry using metallic cavity electrodes (MCEs). The electrolysis was carried out for different durations of time to understand the mechanistic pathway of reduction of ZrO 2 -Fe 2 O 3 . The electro-reduced products were characterized by X-ray diffraction (XRD) technique, scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDS). The reduction intermediates involved Fe, CaZrO 3 , calcia stabilised zirconia (CSZ), Fe 23 Zr 6 , Zr 6 Fe 3 O and Zr 2 Fe. Single cubic C15 phase of ZrFe 2 was obtained in 48 h electrolysis product. ZrFe 1.8 Ni 0.2 was also electrochemically synthesized from its oxide precursors viz. ZrO 2 , Fe 2 O 3 and NiO. Apart from ZrFe 1.8 Ni 0.2 phase, the electro-reduced products had a Zr 2 Ni phase even after 72 h of electrolysis.