Title : Compositionally driven polarization and structural transitions in PZT substituted BiFeO3 ceramics
Abstract:
In recent years, BiFeO3 has shown fascinating properties due to its multistage data storage characteristics and PbZrTiO3 is already known to be one of the best piezoelectric materials so far. In view of this, an effort has been made to synthesize solid solution formation between PbZr0.52Ti0.48O3 (PZT) and BiFeO3 (BFO). X-ray diffraction studies have revealed the solid solution formation over the entire range of compositions with the intermediate structural phase transitions from Rhombohedral (R3C) for x = 0.0 to 0.10, Monoclinic (CC) for x = 0.20 to 0.40, Monoclinic (Cm) for x = 0.50 to 0.70, co-existence of Monoclinic and Tetragonal (Cm+P4mm) for x = 0.70 to 0.90 and Tetragonal for x = 1.0. It is further envisaged that with substitution of PZT, the polarization vector Ps oriented along <111> for x = 0.0 (R3C symmetry), rotates along <100> direction (P4mm symmetry) for x = 1.0 via <110> direction for intermediate values of x i.e. monoclinic phases of Cc and Cm types. Dielectric constant vs temperature plots have shown multiple anomalies at different temperatures with increasing x. The low temperature anomalies are found to occur due to complex defect dipoles formation in these materials and high temperature anomaly is attributed to the intrinsic characteristic of the end members. Dielectric constant has been found to increase and dielectric loss has been found to be decreased with increasing x. A significant decrease in current density with x within the applied electric field up to 4kV/cm has witnessed reduced losses in these materials. Remanent polarization has been found to increase with x, however, remanent magnetization increases with x up to x = 0.30 and thereafter decreases. The decrease in magnetization beyond x = 0.30 may be attributed to the annihilation of spiral spin structure of BFO due to foreign element of do character at Fe sites in BFO.
What will audience learn from your presentation?
- Concept of polarization rotation with structural changes. Structure and property correlation in multiferroics.
- Faculty can learn to use the concept to carryforward the research in this. Since work is pure experimental, so it is a practical solution for them. It may definitely help in designing new problems.
