The interest on the materials containing CeO2 has increased due to the ability of CeO2 to undergo rapid redox cycles. The oxygen partial pressure and the presence of cations with a lower oxidation state influence the reduction behaviour of CeO2. This work reports a comparative study on microstructure, dielectric and piezoelectric properties of Ce- and Ce, Eu doped lead titanate ceramics. The samples with a complex composition were prepared by solid-state reaction of oxide and carbonate powders. Substitutions of Ce4+ and Ce4+, Eu3+ for Pb2+, and Mn4+ for Ti4+ were performed. Nanostructured materials with tetragonal perovskite phase were revealed and investigated by high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED) and X-ray diffraction. The local distribution of the chemical elements was revealed using the wavelength dispersive spectroscopy. The porosity of the ceramics was also investigated. Dielectric permittivity was measured in a wide temperature and frequency ran e. The temperature dependence of the piezoelectric properties is reported. It is found that the substitution of Eu3+ for Ce4+ improves the piezoelectric properties of the PT-type ceramics.
Structure - properties relationships in Ce-doped lead titanate ceramics
2006
Abstract
The interest on the materials containing CeO2 has increased due to the ability of CeO2 to undergo rapid redox cycles. The oxygen partial pressure and the presence of cations with a lower oxidation state influence the reduction behaviour of CeO2. This work reports a comparative study on microstructure, dielectric and piezoelectric properties of Ce- and Ce, Eu doped lead titanate ceramics. The samples with a complex composition were prepared by solid-state reaction of oxide and carbonate powders. Substitutions of Ce4+ and Ce4+, Eu3+ for Pb2+, and Mn4+ for Ti4+ were performed. Nanostructured materials with tetragonal perovskite phase were revealed and investigated by high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED) and X-ray diffraction. The local distribution of the chemical elements was revealed using the wavelength dispersive spectroscopy. The porosity of the ceramics was also investigated. Dielectric permittivity was measured in a wide temperature and frequency ran e. The temperature dependence of the piezoelectric properties is reported. It is found that the substitution of Eu3+ for Ce4+ improves the piezoelectric properties of the PT-type ceramics.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.