The valence and transport property studies for the solid solution Ce1-xEuxO2-delta synthesized by high-temperature and high-pressure

The solid solutions Ce1-xEuxO2-delta (x = 0.10-0.50) were synthesized by hi gh-temperature and high-pressure, The XRD measurement showed that the solid solution was crystallized in cubic fluorite-type structure and the lattice parameter increased with the content of Eu increasing up to x = 0.4. The s olution limit was ca. 0.4 under the condition of 3.6 GPa, 840-1020 degreesC . The XPS data showed that the Eu ions are Eu3+ and trace of Ce4+ ions were reduced to Ce3+ ions during synthesis of high-temperature and high-pressur e. The ionic conduction for Ce0.8Eu0.2O2-delta was measured by impedance sp ectroscopy and it was found that the activation energy was 1.07 eV and the conductivity was 3.43 x 10(-5) S.cm(-1) at 550 degreesC.