Enhanced ferroelectric and piezoelectric responses of (Ba0.85Ca0.15) (Zr0.1Ti0.9)O3 ceramics by Tm3+ amphoteric substitution

The influences of Tm3+ doping on the microstructure and electric properties of (Ba0.85Ca0.15) (Zr0.1Ti0.9)O-3-x mol %Tm2O3 (BCZT-x%Tm) ceramics fabricated by a solid-state method have been studied. BCZT ceramics was orthorhombic phase, and BCZT-x%Tm (x = 0.3-1) ceramics exhibited the coexistence of orthorhombic and tetragonal phases. The correlation of crystal structure and electric properties confirmed that the substitution position of Tm3+ with amphoteric characteristics was related to Tm3+ content. Especially for BCZT-0.5%Tm ceramics, the obvious amphoteric substitution for both A- and B-sites cations of Tm3+ resulted in the formation of defect dipole. The electric properties of BCZT-x%Tm ceramics were dependent on the phase structure, defects and grain size caused by the introduction of Tm3+, and the relevant defect chemical mechanism was illuminated. The enhanced piezoelectric responses (d(33) = 523 pC/N and d(33)* = 645 p.m./V) were achieved in BCZT-0.5%Tm ceramics, and these findings have essential significance in developing high performance lead-free piezoelectric materials.