Cu-modified Pb(Mg1/3Nb2/3)O3-PbZrO3-PbTiO3 textured ceramics with enhanced electromechanical properties and improved thermal stability

Grain-oriented Pb(Mg_1/3Nb_2/3)O₃-PbZrO₃-PbTiO₃ (PMN-PZ-PT) based ceramics were synthesized through templated grain growth via using BaTiO₃ (BT) templates. Although BT templates are partially destroyed by PMN-PZ-PT matrix, CuO addition remarkably promotes [001]_c-oriented grain growth behavior of the ceramics, resulting in an improvement of Lotgering factor F₀₀₁ from ~86% to 98%. Both crystallographic texture and CuO doping increase tetragonality and reduce average domain size of the ceramics dominated by rhombohedral phase. Consequently, 0.50 wt% CuO-doped ceramics (F₀₀₁~98%) exhibit optimum electromechanical properties: d₃₃~860 pC/N, d₃₃×g₃₃~48.6 × 10^?12 m²/N, k_p~0.80, E_c~7.2 kV/cm, tan δ~0.8% and T_c~222 °C. In addition to ~3.7 times and 6.6 times higher d₃₃ and d₃₃×g₃₃, those ceramics possess about 240% enhanced piezoelectric strain and much better thermal stability (S_max/E_max variation ≤2% between RT and 150 °C) relative to non-textured counterpart. This work offers a good paradigm for simultaneously exploring high piezoelectric response and good temperature stability in piezoceramics, benefiting the development of next-generation advanced electromechanical devices.     

Modified Pb(Mg1/3Nb2/3)O3-PbZrO3–PbTiO3 ceramics with high piezoelectricity and temperature stability

There is a great demand to develop ferroelectric ceramics with both high piezoelectric coefficient and broad temperature usage range for emerging electromechanical applications. Herein, a series of Sm³⁺-doped 0.25Pb(Mg_1/3Nb_2/3)O₃-(0.75−x)PbZrO₃-xPbTiO₃ ceramics were fabricated by solid-state reaction method. The phase structure, dielectric and piezoelectric properties were investigated, where the optimum piezoelectric coefficient d₃₃ = 745 pC/N and electromechanical coupling factor k₃₃ = 0.79 were obtained at the morphotropic phase boundary composition x = 0.39, with good Curie temperature T_C of 242°C. Of particular importance is that high-temperature stability of the piezoelectric and field-induced strain was obtained over the temperature range up to 230°C for the tetragonal compositions of x = 0.40. The underlying mechanism responsible for the high piezoelectricity and temperature stability is the synergistic contribution of the MPB and local structural heterogeneity, providing a good paradigm for the design of high-performance piezoelectric materials to meet the challenge of piezoelectric applications at elevated temperature.