Tetragonal (Ba, Ca) (Zr, Ti)O3 textured ceramics with enhanced piezoelectric response and superior temperature stability

Lead-free ceramics with both high piezoelectric response and good temperature stability are urgently demanded for electromechanical conversion devices. Unfortunately, owing to coexistence of polymorphic phases near room temperature (RT), enhanced piezoelectric properties were usually achieved with occurrence of strong temperature dependence in modified BaTiO3 (BT)-based ceramics. In this work, we demonstrate that tailoring grain orientations of tetragonal BT-based ceramics can effectively produce substantially enhanced and thermally stabilized piezoelectric response. Both <001>c- and <111>c-oriented tetragonal (Ba0.85Ca0.15) (Zr0.05Ti0.95)O3 (BCZT) ceramics with texture degrees F>90% were synthesized via templated grain growth. Interestingly, the ceramics textured along the <001>c polar axis show much higher microscopic and macroscopic piezoelectric properties than those with nonpolar <111>c texture, indicating an “extender” ferroelectricity nature. Compared with randomly oriented samples, the <001>c-oriented ceramics exhibit simultaneously ∼1.6 times higher piezoelectric strain d33∗ (∼760 pm/V), 4.4 times higher piezoelectric figure of merit d33×g33 (8.8 × 10−12 m2/N), and better temperature stability (strain variation ≤5% between RT and 110 °C). Such thermally stabilized strain response can be mainly attributed to wide temperature range of tetragonal phase and stable domain structure. This work provides a promising route for further developing lead-free piezoceramics with high and temperature-insensitive performance, which can greatly broaden their application areas.