A PPT from orthorhombic to tetragonal phase around room
temperature was identified in the (Ba1−xCax)(Ti0.94Sn0.06)O3
ceramics at 0.02 < x < 0.04. BCST ceramics at PPT composition
exhibit extremely high piezoelectric coefficient of
d33 = 440 pC/N and dielectric constants of εr = 6900. Our work
provides a new way for designing lead-free materials with both
of high piezoelectric properties and dielectric properties.