Structural models for intergrowth structures in the phase system Al2O3-TiO2

Artikel i vetenskaplig tidskrift, 2005

The phase system Al2O3-TiO2 was investigated in the compositional range from 48:52 to 62:38 mol% Al2O3:TiO2. The samples were prepared by melting the binary oxides in an arc-imaging furnace and the obtained samples were examined by powder X-ray diffraction. The recorded powder patterns could be interpreted in terms of intergrowth structures consisting of two basic building blocks, which were deduced from the known crystal structures of beta-Al2TiO5 and Al6Ti2O13. The structure of a new ordered compound with the formula Al16Ti5O34 is proposed. The thermal stability was estimated from DTA and tempering experiments and showed that all prepared samples decompose at temperatures around 800 degrees C into the binary oxides corundum and titania.