Abstract (Ba 1- x Ln 2 x /3 )(Co 0.7 Mg 0.3 ) 1/3 Nb 2/3 O 3 (0.01 ≤ x ≤ 0.04, Ln=La, Nd) ceramics were synthesized by solid-state reaction process and their sintering behavior, microstructure and microwave dielectric properties were investigated in this paper. The X-ray diffraction results show that all the samples exhibit a single peroskite phase except for the Nd-substituted compositions with x > 0.02. The sinterability and grains distribution are improved by the La-substitution. Though the long range ordering degrees on B-site are similar in the Ln-substituted compositions, the size of ordered domains observed by HRTEM images are quite different. Compared with the Nd-subsituted compositions, the higher Q × f values in the La-substituted compositions are mainly attributed to the better densification and ordered domain structure with lower energy barriers. Both e r and τ f values increase slightly with the increase of Ln-substitution. A good combination of microwave dielectric properties was obtained in the La-substituted composition with x = 0.01: e r = 32.5, Q × f = 79812 GHz, τ f = 4 ppm/°C.

中文翻译：

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Ba 1-x Ln 2x/3 (Co 0.7 Mg 0.3 ) 1/3 Nb 2/3 O 3 (Ln=La, Nd)陶瓷的结构有序性和微波介电性能

摘要 (Ba 1- x Ln 2 x /3 )(Co 0.7 Mg 0.3 ) 1/3 Nb 2/3 O 3 (0.01 ≤ x ≤ 0.04, Ln=La, Nd)本文研究了它们的烧结行为、微观结构和微波介电性能。X 射线衍射结果表明，除了 x > 0.02 的 Nd 取代组合物外，所有样品都表现出单一的钙钛矿相。La 取代改善了烧结性和晶粒分布。尽管在 Ln 取代的组合物中 B 位上的长程有序度相似，但 HRTEM 图像观察到的有序域的大小却大不相同。与 Nd 取代的组合物相比，La 取代组合物中较高的 Q × f 值主要归因于更好的致密化和有序的域结构，具有较低的能垒。er 和 τ f 值都随着 Ln 取代度的增加而略有增加。在 La 取代的组合物中获得了良好的微波介电性能组合，x = 0.01：er = 32.5，Q × f = 79812 GHz，τ f = 4 ppm/°C。