Samarium-Doped Lead Magnesium Niobate-Lead Titanate Ceramics Fabricated by Sintering the Mixture of Two Different Crystalline Phases

The fabrication method plays a key role in the performance of lead magnesium niobate–lead titanate-based ceramics. (1 − w)[Pb(Mg(1/3)Nb(2/3))(0.67)Ti(0.33)O(3)]-w[Pb(1−1.5x)Sm(x)(Mg(1/3)Nb(2/3))(y)Ti(1−y)O(3)] piezoelectric ceramics were prepared by sintering the mixture of two different crystalline phases in which two pre-sintered precursor powders were mixed and co-fired at designated ratios (w = 0.3, 0.4, 0.5, 0.6). The X-ray diffraction results show that all the ceramics presented a pure perovskite structure. The grains were closely packed and the average size was ~5.18 μm based on observations from scanning electron microscopy images, making the ceramics have a high density that is 97.8% of the theoretical one. The piezoelectric, dielectric, and ferroelectric properties of the ceramics were investigated systematically. It was found that the properties of the ceramics were significantly enhanced when compared to the ceramics fabricated using the conventional one-step approach. An outstanding piezoelectric coefficient d(33) of 1103 pC/N and relative dielectric permittivity ε(33)/ε(0) of 9154 was achieved for the ceramics with w = 0.5.