Large Electromechanical Strain in Lead‐Free Binary System K _0.5 Bi _0.5 TiO ₃ ‐ Bi ( Mg _0.5 Ti _0.5 ) O ₃

Abstract

Solid solution formation in the lead‐free binary system (1− x ) K 0.5 Bi 0.5 TiO 3 − x Bi ( Mg 0.5 Ti 0.5 ) O 3 has been studied for compositions x ≤ 0.12. X‐ray powder diffraction shows single‐phase perovskite for x < 0.1, and a mixed phase region between tetragonal and pseudocubic phases for compositions 0.04 ≤ x ≤ 0.06. Large electromechanical strains of ~0.3% at fields of 50 kV/cm are recorded in the mixed phase region, with d 33 * ( S max / E max ) values of ~600 pm/V. The materials sustain polarization at low electric fields with remnant polarization ~18 μC/cm 2 and coercive field ~20 kV/cm for x = 0.06. Relative permittivity‐temperature plots display relaxor characteristics, with peak temperature ~340°C.