Growth and performance characterization of relaxor-based ferroelectric crystal PMN-PT-PZ with high phase transition temperature

摘要

? 2016, Chinese Ceramic Society. All right reserved. ? 2016, Chinese Ceramic Society. All right reserved. According to the molar ratio of 0.624Pb(Mg 1/3 Nb 2/3 )O 3 -0.336PbTiO 3 -0.04PbZrO 3 , PMN-PT-PZ polycrystalline material was prepared by two-step solid-state synthesis at elavated temperature. PMN-PT-PZ relaxor-based ferroelectric crystal with size of Φ25 mm× 90 mm was grown from the stoichiometric melts by vertical Bridgman method. The crystalline phases of the polycrystalline material and as-grown crystal were characterized by XRD. The dielectric, ferroelectric and piezoelectric properties of the PMN-PT-PZ crystal wafers were characterized. The results show that the ternary solid-solution polycrystalline material and single crystal PMN-PT-PZ were verified to be perovskite structure without any pyrochlore phases. Temperature dependence of dielectric permittivity of the crystal wafers exhibits a phase transformation temperature T rt of 130°C and T c of 165-170°C. The piezoelectric coefficient d 33 was measured to be in the range of 1300-1800 pC/N for the crystal wafers with (001)-orientation fabricated from rhombohedral phase region of the crystal boule. The ferroelectric parameters of the crystal wafers were measured as a E c of 4-4.5 kV/cm and a remanent polarization P r of 20-31.5 μC/cm 2 . Compare to PMN-PT single crystal, it is confirmed that PMN-PT-PZ single crystal possesses a higher phase transformation temperature and an increased coercive field. According to the molar ratio of 0.624Pb(Mg 1/3 1/3 Nb 2/3 2/3 )O 3 3 -0.336PbTiO 3 3 -0.04PbZrO 3 3 , PMN-PT-PZ polycrystalline material was prepared by two-step solid-state synthesis at elavated temperature. PMN-PT-PZ relaxor-based ferroelectric crystal with size of Φ25 mm× 90 mm was grown from the stoichiometric melts by vertical Bridgman method. The crystalline phases of the polycrystalline material and as-grown crystal were characterized by XRD. The dielectric, ferroelectric and piezoelectric properties of the PMN-PT-PZ crystal wafers were characterized. The results show that the ternary solid-solution polycrystalline material and single crystal PMN-PT-PZ were verified to be perovskite structure without any pyrochlore phases. Temperature dependence of dielectric permittivity of the crystal wafers exhibits a phase transformation temperature T rt rt of 130°C and T c c of 165-170°C. The piezoelectric coefficient d 33 33 was measured to be in the range of 1300-1800 pC/N for the crystal wafers with (001)-orientation fabricated from rhombohedral phase region of the crystal boule. The ferroelectric parameters of the crystal wafers were measured as a E c c of 4-4.5 kV/cm and a remanent polarization P r r of 20-31.5 μC/cm 2 2 . Compare to PMN-PT single crystal, it is confirmed that PMN-PT-PZ single crystal possesses a higher phase transformation temperature and an increased coercive field.