Lattice Parameter Variation in Nii__xCa_xO Ternary Solid Solutions

摘要

Ternary solid solutions of Nii__xCa_xO (x= 1 to 10 %) are prepared by solid state reaction at 1400°C for 48 hours and characterized with XRD measurement. Single phase ofNii__xCa_xO is observed up to 8 % of Ca doping in NiO and the lattice parameters are found to increase with Ca composition. Thereafter, a secondary phase of CaO suddenly appears for Ca compositions more than 8% and the lattice parameter does not increase appreciably. This observation indicates that lattice of Nii__xCa_xO is not energetically favorable for Ca compositions more than 8% that may lead to the miscibility gap.