High Strain and Piezoelectric Characteristics of Textured Bi0.5(Na0.85K0.15)0.5TiO3 Ceramics

The anisotropy of polarization and strain behavior in textured Bi
_0.5
(Na
_0.85
K
_0.15
)
_0.5
TiO
₃
ceramics are investigated for lead-free piezoelectric ceramics actuators. The textured Bi
_0.5
(Na
_0.85
K
_0.15
)
_0.5
TiO
₃
ceramics are fabricated by reactive templated grain growth (RTGG) using plate-like Bi
₄
Ti
₃
O
₁₂
particles. RTGG[//] (sliced parallel to the casting direction) and RTGG[square] (sliced perpendicularly to the casting direction) specimens show preferred orientation to <001>
_pc
and <110>
_pc
, respectively. RTGG[//] specimen has relatively high piezoelectric coefficient of (d
₃₃
) ~335 pm/V and electric field induced strain levels of 0.067% at 20 kV/cm. This values were 86% higher than those of RTGG[ square] specimen. <001>
_pc
textured polycrystalline BNKT ceramics, prepared by RTGG, are a strong candidate for lead-free piezoelectric materials of actuators.