고온 압전 기기 응용을 위한 textured (Bi,Sm)ScO₃-PbTiO₃ 세라믹의 온도 안정 특성

Temperature-stable Characteristics of Textured (Bi,Sm)ScO₃-PbTiO₃ Ceramics for High-temperature Piezoelectric Device Applications

In this study, textured 0.38(Bi0.97Sm0.03)ScO3-0.62PbTiO3 (0.38BSS-0.62PT) ceramics with high Curie temperature were evaluated to assess temperature stable characteristics for high-temperature piezoelectric device applications. The 4 vol% BaTiO3 incorporated 0.38BSS-0.62PT ceramic was fabricated by conventional tape casting. Textured 0.38BSS-0.62PT ceramic was successfully produced at sintering temperature of 1150°C by textured grain growth (TGG). Textured 0.38BSS-0.62PT ceramic exhibited a high degree of crystal orientation of 94% in the [001]-direction. It also showed excellent dielectric and piezoelectric properties, (ε T33/ε 0 of 1746, d 33 of 719 pC/N, k p of 61.8% and g 33 of 45×10-3Vm/N, respectively). In addition, it also exhibited relaxor-like ferroelectric characteristics with a large relaxation coefficient (γ) of 1.77 along with high Curie temperature of approximately 373℃. Its temperature stability was satisfactory, resulting from in-situ d 33 and k p, which were lower than 10% below Curie temperature. The electro-strain also showed thermally stable characteristics. Therefore, it is considered that the textured 0.38BSS-0.62PT ceramic has potential for high-temperature piezoelectric device applications.