Composition-independent Curie point (T-c) in ferroelectric (1-x)PbTiO3-xBi(Li1/2Nb1/2)O-3 solid solution

A new ferroelectric solid solution (1 - x)PbTiO3-xBi(Li1/2Nb1/2)O-3 has been explored to develop high-temperature piezoelectric material. An interesting observation has been found regarding its Curie point (T-C) and tetragonal lattice strain (c/a - 1). With increasing composition (x), the Curie point (T-C) decreases up to x = 0.10 and thereafter remains constant. In concurrence with the T-C, the tetragonal lattice strain (c/a - 1) follows a similar trend. Neutron powder diffraction analysis suggests this anomalous behavior is due to the robust off-centering characteristic of the Bi+3 ion 6S(2) lone pair effect at the A-site compared to ions at B-site.