Nickel aluminate spinels were prepared by solid-state reaction. Their lattice parameters (a(0)) changed with preparation temperature, which was explained by cation distribution, vacancies formation, and cation entrance. When the preparation temperature increased from 1100degrees to 1200degreesC, a(0) decreased with temperature as the result of the uptake of Al2O3. After 1200degreesC, a(0) increased to temperature, which was attributed to some Ni2+ exchange with tetrahedral sites and some vacancies occupancy by Ni2+ and Al3+.