Solid state reaction in nanometer scale at the interface between TiN and MgO can result in formation of Mg3TiO4 particles which has not reported before. The structure of the newly found oxide is characterized with spherical-aberration corrected scanning transmission electron microscopy at atomic resolution with X-ray energy dispersive spectroscopy. The nanosized Mg3TiO4 oxide particles formed in MgO underneath the epitaxial TN film with cube-on-cube coherent relationship with both MgO and TiN, i.e. TiN(0 0 1) || Mg–Ti–O(0 0 1) || MgO(0 0 1) and TiN[1 1 0] || Mg–Ti–O[1 1 0] || MgO[1 1 0]. Mg3TiO4 is identified to have cubic structure (lattice parameter a = 0.842 nm) with space group of Fd3¯m.
- Electron microscopy