Synthesis and structural study of a self-organized MnTiO3–TiO2 eutectic

• We have grown the MnTiO3–TiO2 eutectic by the micro-pulling-down method.
• We report a qualitative and quantitative analysis of this eutectic microstructure.
• MnTiO3–TiO2 eutectic exhibits a three dimensional TiO2 (in form of rutile) net embedded in the MnTiO3 phase.
• The refinement of the structure is higher for higher pulling rates.
• MnTiO3–TiO2 potential application is in photoelectrochemistry.

A microstructured manganese titanate – titanium dioxide, MnTiO3–TiO2, hybrid eutectic has been grown by the micro-pulling-down method from a TiO2 57 mol.% – MnO 43 mol.% composition. X-ray powder diffraction verifies that two phases have been formed: rhombohedral MnTiO3 and tetragonal TiO2. The TiO2 phase forms a three-dimensional network of micron-scale oval precipitates interconnected with c.a. 0.5 μm in thickness lamellas and the MnTiO3 is the matrix phase. The two TiO2 precipitate types grow in different crystallographic orientations, which results in this complex geometry made of faceted and non-faceted inclusions. The lamellas grow in the [010] orientation in which a 2-fold axis is present, while the oval precipitates grow in the [001] orientation in which the 4-fold screw axis is present. A qualitative and quantitative analysis of the eutectic microstructure is presented. The MnTiO3–TiO2composite is interesting due to its potential application in photoelectrochemistry.

Figure optionsDownload as PowerPoint slide