Piezoelectric and pyroelectric properties of Mn-doped 0.36Pb(In_1/2Nb_1/2)O₃–0.36Pb(Mg_1/3Nb_2/3)O₃–0.28PbTiO₃ ceramics

0.5 mol% Mn-doped 0.36Pb(In_1/2Nb_1/2)O₃–0.36Pb(Mg_1/3Nb_2/3)O₃–0.28PbTiO₃ (Mn-PIMNT) ceramics were fabricated by a two-step precursor method. The phase structure, morphologies, and temperature-dependent dielectric, ferroelectric, piezoelectric, and pyroelectric properties were studied. The results indicated that the Mn-PIMNT ceramics had pure perovskite phase and uniform grain distribution. Meanwhile, it exhibited ultrahigh piezoelectric coefficient d₃₃ of 235 pC/N, high-power figure of merit (FOM) of 60,160 pC/N, large remnant polarization P_r of 34.57 µC cm⁻² and coercive field E_C of 12.97 kV cm⁻¹, which were much better than that of binary Mn-PMNT ceramics. Moreover, by Mn ions-doping, giant pyroelectric coefficient p up to 4.8 × 10^–4 C m⁻² K⁻¹ was obtained and the figure of merits for the detectivity F_d reached 2.317 × 10^–5 Pa^−1/2, higher than PIMNT ceramics. Combined with the outstanding piezoelectric and pyroelectric properties as well as high ferroelectric rhombohedral to tetragonal phase transition temperature T_rt (up to 146 ℃) and ferroelectric tetragonal to cubic phase transition T_C of 188 ℃, it is suggested that the Mn-PIMNT ceramics are an excellent candidate for piezoelectric and pyroelectric devices.