Enhanced temperature stability and tailored electromechanical response in (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 piezoceramics through rare earth modification

(Ba,Ca)(Zr,Ti)O-3 piezoceramics are deemed as one of potential lead-free alternatives to commonly used lead-based piezoelectric ceramics because of their high piezoelectric properties. However, in the process of improving their electrical properties, it tends to cause significant deterioration of thermal, frequency, and fatigue stability for electromechanical response, which will impede the commercialization of piezoelectric materials. Herein, we designed a strategy using the rare earth to modify BCZT lead-free piezoceramics so as to solve the above mentioned challenges. In this work, for Ho-modified BCZT lead-free ceramics, we achieved not only high electromechanical response with S-max/E-max=550pm/V and large piezoelectric coefficient d(33)=521pC/N, but also the enhanced temperature stability featured by <2% variation for d(33) in the general operating temperature range of 20 degrees C and 70 degrees C. In addition, large electrostrictive coefficient Q(33) of 0.045m(4)/C-2 was also realized in this modified materials while still maintaining good temperature stability. More interestingly, this modified materials also performed excellent fatigue endurance, evidenced by<3% variation for the remnant polarization (P-r) and S-max/E-max after 10(5) cycles. The complex impedance spectra verified that the boosted fatigue resistance was mainly attributed to the decrease of the defect density originating from the reduced oxygen vacancies. These results demonstrate that the introduction of rare earth into BCZT is an effective way to tailor temperature stability and electromechanical responses.