Influence of superlattice and antiphase domain boundaries on dielectric loss in Ba[Mg_(1/3)(Nb_(x/4)Ta_((4-x)/4))_(2/3)]O_3 ceramics

摘要

The Ba[Mg_(1/3)(Nb_(x/4)Ta_((4-x)/4))_(2/3)]O_3 ceramics (x = 0, 1, 2, 3, and 4) synthesized by a solid reaction method were sintered at 1650℃ for 9 h. The quality factor (Q, ～ 1/tan δ, tan δ: dielectric loss) and superlattice structure were investigated by the cavity method and high-resolution electron microscopy. The excellent Q value of 17 600 obtained at appropriate Nb content ( x = 1 ). The disorder structure (superlattice modulation ～0.41 nm), 1:2 ordering structure (superlattice modulation ～0.71 nm) and antiphase domain boundary (APB) were revealed in Ba[Mg_(1/3)(Nb_(x/4)Ta_((4-x)/4))_(2/3)]O_3 ceramics. The formation of extra ordering structure (superlattice modulation～1.24 nm) on the APBs contributed to the improved Q value with the stabilization of ordering-induced domain boundaries.