TITLE:
Enhanced Ferroelectric and Converse Piezoelectric Properties of Dense Lead-Free Na0.4K0.1Bi0.5TiO3 Ceramics for Actuator Applications
AUTHORS:
N. Shara Sowmya, Pravin Varade, Narayanan Venkataramani, Ajit R. Kulkarni
KEYWORDS:
Lead-Free Piezoelectric, Morphotropic Phase Boundary, Converse Piezoelectric Coefficient, Actuator
JOURNAL NAME:
Advances in Materials Physics and Chemistry,
Vol.9 No.1,
March
12,
2019
ABSTRACT: In
this work, lead-free Na0.4Bi0.5 TiO3-K0.1Bi0.5TiO3 (NKBT) piezoelectric ceramics were prepared by the solid-state reaction
method and their structural, ferroelectric and dielectric properties were
systematically studied. NKBT sintered at 1150℃ for 4 h exhibited highly dense
(96% - 98% of the
theoretical density) and uniform grains of size 1.1 μm. The coexistence of
tetragonal (P4bm) and
rhombohedral (R3c) phases due
to the presence of morphotrophic phase boundary for the chosen composition has
been confirmed by the Rietveld refinement studies. Enhanced ferroelectric
properties such as remnant polarization (Pr) and coercive field (EC)
are found to be 37 μC/cm2 and 30 kV/cm, respectively. The optimized
synthesis procedure for NKBT ceramics resulted in enhanced strain (%) and
converse piezoelectric coefficient (d33*) of 0.3 % and 554 pm/V which
is attributed to smaller grain size and switching of non 180o domains. NKBT
ceramics with such excellent piezoelectric properties can be considered as a
promising candidate for actuator applications.