Aqueous co-precipitated Ti _0.5 Sn _0.5 O ₂ nanopowders as precursors for dense spinodally decomposed ceramics

Spinodal decomposition in the TiO₂-SnO₂ system produces TiO₂ rich/SnO₂ rich nano-wide lamellae. The high density of coherent interfaces is expected to reduce thermal conductivity of the ceramic without blocking electron transport. These semiconductors could therefore be candidates for environmental friendly oxide thermo-electrics. However, dense materials are difficult to obtain by conventional sintering from a mixture of TiO₂ and SnO₂ powders due to evaporation of tin oxide. The article presents a novel route to produce, by aqueous co-precipitation, Ti_0.5Sn_0.5O₂ nanopowders as precursors for dense ceramics. The nanostructure developed by spinodal decomposition inside the grains of the as obtained dense Ti_0.5Sn _0.5O₂ ceramic is shown to be comparable to that of porous Ti_0.5Sn_0.5O₂ ceramic obtained by conventional method.