Fabrication of near-zero thermal expansion (FexSc1−x)2Mo3O12–MoO3 ceramic composite using the reaction sintering process

(FexSc1−x)2Mo3O12–MoO3 ceramic composites (x=0, 0.1, 0.2, 0.3) with negative thermal expansion (FexSc1−x)2Mo3O12 particles dispersed in a matrix of MoO3 were fabricated from oxides using a melt reaction process at 960°C. Microscopy and Energy Dispersive X-ray spectroscopy show particles of iron/scandium molybdate uniformly distributed in the MoO3 matrix. The matrix has a layered plate-form shape with cleavage structure. The electrical resistivity of the composites is >106 Ω·cm. The mean coefficient of linear thermal expansion of the composites increased from −3.5×10−6 K−1 when x=0 to near-zero values (−0.2 to +0.2×10−6 K−1) when x=0.2. This near-zero thermal expansion is nearly constant over the temperature range 25–500°C.