Evolution of relaxor properties in lanthanum (La) doped barium zirconate titanate

ABSTRACT

La doped BZT ceramics were synthesized by solid state reaction route. XRD and SEM indicated predominantly single phase microstructure. Raman spectroscopy supported La doping at A-site. Dielectric properties revealed a diffuse phase transition in Ba(Ti_0.8Zr_0.2)O₃. La doping of 1 atomic % enhanced the FWHM to 200 K at a frequency of 1 kHz. Further increase in La doping introduced relaxor properties but FWHM was reduced. Relaxor properties were evaluated by modified Curie-Weiss law. The degree of relaxation increased from 1.31 to 2.07 as the La doping was increased from 0 to 3 atomic %, thereby yielding a complete relaxor phase.

KEYWORDS:

• Barium zirconate titanate
• ferroelectric
• relaxor
• La doping

Acknowledgments

Authors acknowledge (i) financial support via UGC-BSR start-up grant (F.30–2/2014(BSR)) and DST Purse grant, (ii) access to PE loop tracer at SCNS, JNU and (iii) access to SEM at AIRF, JNU (DBT grant no. BT/PR3130/INF/22/139/2011).