Synthesis, characterization and lattice thermal expansion of some compounds in the system Gd2CexZr2−xO7

Synthesis, characterization and lattice thermal expansion studies of compounds formed in the Gd2O3-CeO2-ZrO2 system with general stoichiometry Gd2CexZr2−xO7 is being reported. The products obtained were characterized by powder XRD for phase purity and the unit cell parameters determination. It was observed that only 5 mol% of Ce4+ is soluble in the lattice of Gd2Zr2O7. Further addition of Ce4+ leads to the formation of fluorite-type phase over a wide range of compositions, i.e. from Gd2Ce0.2Zr1.8O7 to Gd2Ce1.7Zr0.3O7. The further extreme Ce4+ rich compositions show the formation of C-type cubic phase. The lattice thermal expansion studies for the end members of the series and Gd2Ce0.1Zr1.9O7 were carried out by HT-XRD in the temperature range 20-1200 °C. The coefficients of lattice thermal expansion are 11.6(5) × 10−6 C−1 for Gd2Zr2O7, 11.4(5) × 10−6 C−1 for Gd2Ce0.1Zr1.9O7 and 13.8(5) × 10−6 C−1 for Gd2Ce2O7.