Nickel(II) titanate

Nickel titanate is an inorganic compound with the chemical formula NiTiO₃. It is a coordination compound between nickel, titanium and oxide ions. It has the appearance of a yellow powder.

Structure

Nickel titanate crystallizes at 600 °C and is stable at room temperature and normal pressure in an ilmenite structure with rhombohedral R3 symmetry. It consists of alternating layers of Ni and Ti along the rhombohedral axis with O layers between them.
Another description of nickel titanite's illemite structure consists of a pseudo close packed hexagonal array of O²⁻ ions with two thirds occupied by an ordered hexagonal like cation. The average crystallite's size was estimated at 42 nm with lattice constants of a = 5.032 Å, b = 5.032 Å, c = 4.753 Å.

Nickel titanate can be prepared by the autocombustion of a mixture of titanium isopropoxide, nickel(II) nitrate, and alanine in isopropyl alcohol solution. The resulting dark green product is then calcined.
Another method involves heating NiO and TiO₂ at 1350 °C for three hours.
NiTiO₃ residue is formed in the thermal decomposition of the heterobimetallic complex Ni₂Ti₂₂₆₄.

Nickel titanate is used as a yellow pigment. It has been used as a catalyst for toluene oxidation.
It is of research interest as an electronic material due to its high dielectric constant, weak magnetism, and semiconductivity. It has received attention as a possible candidate for multiferroic materials capable of magnetization through the application of an electric field.