Compositional Fluctuation Induced Relaxor Antiferroelectric Ordering in La Modified (Bi0.5Na0.5)0.94Ba0.06TiO3: Effect of Polar Nanoregions

The La
³⁺
modified lead free Bi
_0.5
Na
_0.5
TiO
_3-
BaTiO
₃
/BNBTO solid solutions near morphotropic phase boundary [((Bi
_0.94
La
_0.06
)
_0.5
Na
_0.5
)
_0.94
Ba
_0.06
TiO
₃
/BLNBTO and ((Bi
_0.5
Na
_0.5
)
_0.94
Ba
_0.06
)
_0.91
La
_0.06
TiO
₃
/BNBLTO] have been prepared by the high temperature solid state reaction method. The crystal structure of BLNBTO transfers from Rhombohedral (R3c) to pseudocubic symmetry (P4bm) with the anti-polar phase in BNBLTO, which is confirmed by the Rietveld refinement of the XRD patterns. The microstructural analysis of the samples has been carried out by the field emission electron microscopy. The temperature dependent dielectric permittivity shows the diffuse phase transition (DPT). The degree of DPT has been estimated by the modified Curie-Weiss law and, found to be 1.671 and 1.716 for BLNBTO and BNBLTO respectively. The compositional fluctuation induced relaxor antiferroelectric ordering has been confirmed by the ferroelectric hysteresis loops. The energy storage density of BNBLTO has been found to be 0.376 Jcm
^-3
. The present work provides the role of compositional engineering to tune the physical properties of the material for technological applications.