Influence of Ti addition on thermophyscial properties of Sm2Ce2O7 oxides

Abstract

Sm2(Ce1-xTix)2O7 (where x = 0, 0.1,0.3, 0.5) solid solutions were synthesized by conventional solid state reaction method using Sm2O3, CeO2 and TiO2 as raw reactants. The synthesized powders were pressed into pellets by cold isostatic pressing and pressure-less sintered at 1600 °C for ten hours. Their phase-structure and thermophysical properties were studied. The synthesized samples exhibit single defect fluorite-type structure. Due to the phonon scattering by substitutional atoms, the thermal conductivities of the Sm2(Ce1-xTix)2O7 solid solutions decrease with the increasing Ti4+ content over the entire temperature range, which are significantly lower than that of yttrium stabilized zirconia (YSZ). The thermal expansion coefficients of the prepared Sm2(Ce1-xTix)2O7 solid solutions also decrease with the increasing Ti4+ fraction, which can be attributed to the lower titanium ion radius.

Keywords

• Ti-doped Sm2Ce2O7
• solid solutions
• thermal conductivity
• thermal expansion coefficient