Abstract
The effects of Pr substitution in the structure and ferroelectric response for theSr1−xPrxBi2Ta2O9 (SBT-Pr) compound have been studied. Rietveld refinement of the x-ray diffractionpatterns indicates that the Pr ion progressively replaces the Sr site in theA 21am space group structure. The solubility of Pr in solid solution is around15%. The replacement induces a change in the crystal structure and, as aconsequence, the dielectric properties are affected. The ferroelectric transition atTm∼558 K is shifted to lowertemperatures, Tm∼413 Kfor x = 0.15 composition.Apparently, the tilt angle (α) associated with the c-axis does not play an important role since it remains essentially constant. However, the rotation in theab-plane(β) as well as the octahedral distortion observed are strongly related to the coupling betweenTm and x. A relaxor-type transition is observed as Pr is increased, leading to polarmicroregions above the nominal ferroelectric transition. The local disorderinduced by the Pr ion is confirmed by the continuous increase in the diffusenesscoefficient according to Isupov’s model. These facts hinder the displacement of theTaO6 octahedrawith respect to Bi2O2 along the polarization axis, decreasing the polarization values.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
