X-ray photoelectron study of calcium cerium titanate ceramics
MetadataShow full item record
The elemental and ionic quantitative compositions and oxidation states of elements in the ceramics CaCe0.9Ti2O6.8 (I) and CaCeTi2O7 (II)-matrices for long-term storage of long-lived radionuclides constituting hi-h-level radioactive wastes-are studied by X-ray photoelectron spectroscopy. Compound I, obtained at a pressure of 300 MPa and T = 1400degreesC in air, has two types of surface cerium ions, 63 at. % Ce3+ and 37 at. % Ce4+; compound II, fabricated at a pressure of 300 MPa and T= 1300degreesC in an oxygen atmosphere, also has two types of surface ions, 36 at. % Ce3+ and 64 at. % Ce4+, which agrees satisfactorily with X-ray powder diffraction and scanning, electron microscopy data. On exposure to environmental conditions, calcium and/or cerium carbonates can form on the surface of the ceramics under consideration, which entails their failure.