Author/Authors :
Deluca، نويسنده , , Marco and Vasilescu، نويسنده , , Catalina A. and Ianculescu، نويسنده , , Adelina C. and Berger، نويسنده , , Daniela C. and Ciomaga، نويسنده , , Cristina E. and Curecheriu، نويسنده , , Lavinia P. and Stoleriu، نويسنده , , Laurentiu and Gajovic، نويسنده , , Andreja and Mitoseriu، نويسنده , , Liliana and Galassi، نويسنده , , Carmen، نويسنده ,
Abstract :
Single phase and dense BaTi1−xZrxO3 (BTZ) ceramics (x = 0.10, 0.15 and 0.20) were obtained from nanopowders synthesised by the modified Pechini method. The evolution of both Raman spectra and low-field dielectric properties against temperature indicated the occurrence of diffuse ferroelectric–paraelectric phase transitions for all the BTZ compositions under investigation. The evolution of first-order reversal curves (FORC) diagrams emphasised the crossover from the ferroelectric towards the relaxor state as the Zr content increased. Lower values of the Curie temperatures than those usually reported earlier in the literature were obtained for all the BTZ samples analysed here. The high-field tunability data completed the low-field and Raman results, showing that by increasing Zr addition, multiple polarisation components with various weights are responsible for the dielectric and ferroelectric properties.
Keywords :
Ferroelectric–paraelectric phase transition , Sol–gel processes , BaTiO3 and titanates , dielectric properties , Spectroscopy