Improvement of temperature-stability and piezoelectric performance of Pb(In0.5Nb0.5)O3–PbTiO3 crystals via Nd doping

High-performance relaxor-PbTiO₃ ferroelectric crystals have been widely applied in transduces, sensors and so on. The ferroelectric phase transition temperature restricts their application in automobile, deep oil-well detection and aerospace which requires high thermal stability. Decreasing the effects of ferroelectric phase transition is a promising strategy for improving the thermal stability. Here, the design strategy is structural regulation via rare earth doping tetragonal Pb(In_1/2Nb_1/2)O₃–PbTiO₃ (PIN-PT) crystals. The d₃₃, k₃₃ and T_C of 001]_c-oriented Nd-PIN-PT crystals are 750 pC/N, 87%, 250 °C. Compared with the d₃₃ of tetragonal 0.61PIN-0.39 PT crystals (540 pC/N) and tetragonal 0.35PIN-0.26 Pb(Mg_1/3Nb_2/3)O₃ (PMN)-0.39 PT crystals (530 pC/N), the d₃₃ of Nd-PINT crystals enhance by 39% and 41%. In addition, Nd-PIN-PT crystals have Q_m of 110, which is larger than rhombohedral relaxor-PbTiO₃ ferroelectric crystals (~50). Although the d₃₃ of Nd-PIN-PT crystals is lower than that of rhombohedral relaxor-PT ferroelectric crystals, the d₃₃ and k₃₃ are stable up to 250 °C, which is higher than tetragonal PIN-PMN-PT crystals (210 °C). The high thermal stability of piezoelectric properties is related to the high thermal stability of domain after poling. This work provides a design strategy for high thermal stability ferroelectric crystals.