Synthesis and characterization of nanocrystalline Ce0.8Nd0.2O2-delta solidsolution

The solid solution Ce0.5Nd0.2O2-delta was prepared by sol-gel method. The X RD measurements showed that the product obtained by sintering the fresh gel at 200 degreesC crystallized in a single fluorite structure and its grain size was calculated to be ca. 7.2 nm by Scherrer formula, With the increase of sintering temperature, the grain size of solution increases. A few of C e3+ ions were detected by EPR measurement. The first-order Raman spectra of the solid solutions exhibited two peaks. The strong band F-2g mode at a lo wer frequency is assigned to symmetric breathing mode of the oxygen atoms a round cerium ions, while the weak band at ca. 570 cm(-1) is related with th e existence of oxygen vacancies. With the grain decrease, the F-2g mode shi fts to the lower frequency, while the half-height width becomes broaden. Th e ionic conductivity for the solid solution Ce0.5Nd0.2O2-delta at 500 degre esC (sigma (500 degreesC)) is 2,65 X 10(-3) S cm(-1), and the activation en ergy is 0.82 eV.