Balancing piezoelectricity, mechanical strength, and thermophysical stability in BCZT ceramics via Li2O-Sb2O3 co-doping

The strategic incorporation of Li 2 O-Sb 2 O 3 (LS) into Ba 0.90 Ca 0.10 Zr 0.10 Ti 0.90 O 3 (BCZT) ceramics was investigated to achieve an enhancement of functional properties via a conventional solid-state reaction route. Li + (A-site) and Sb 3+ (B-site) co-doping is suggested to have induced a controlled tetragonal-to-orthorhombic phase transition and a systematic lattice contraction, as indicated by XRD Rietveld refinement and Raman spectroscopy. A moderate LS concentration ( x = 0.24 wt%) yields optimal densification, grain growth, and phase coexistence, resulting in a favourable piezoelectric coefficient ( d 33 , 166.8 pC/N), enhanced remanent polarisation ( P r , 12.01 μC/cm 2 ), and improved fracture strength ( K , 118.6 MPa). In contrast, excessive x could promote grain refinement, local compositional disorder, and the possible formation of polar nanoregions, leading to pronounced relaxor behaviour, a higher coercive field, and degraded piezoelectric performance. Furthermore, the thermal expansion coefficient is effectively tuned via doping. The work suggests that precise control of LS concentration enables a harmonious balance among electrical, mechanical, and thermophysical properties in BCZT materials, indicating that these materials may be suitable for certain piezoelectric applications requiring moderate but comprehensive performance.