Dielectric Properties and the Influencing Factors of Li 3 Mg 2 SbO 6 Ceramics Synthesized Through the Mixed Oxide Method

ABSTRACT Rock‐salt structured Li 3 Mg 2 SbO 6 ceramics synthesized by a two‐stage solid‐phase method have attracted much attention due to the low dielectric constant and small negative τ f value. In efforts to simplify the preparation process and reduce costs, Li 3 Mg 2 SbO 6 was synthesized through a mixed oxide route using Sb 2 O 3 as the antimony source, and found that its applicability was limited due to poor sintering ability and low performance likely caused by volatilization and oxidation of Sb 2 O 3 . In this work, Li 3 Mg 2 SbO 6 ceramic was synthesized via the mixed oxide method using Sb 2 O 5 with high thermal stability and low volatilization as the antimony source. The use of Sb 2 O 5 as the antimony source reduces observed secondary phases compared with literature reports using Sb 2 O 3 ; moreover, we confirm this claim quantitatively below through TG–DSC of precursors and ICP‐MS measurement of sintered samples. All samples possessed rock salt structures with a space group of Fddd (70) and a well‐formed appearance. The samples sintered at 1450°C exhibited superior microwave dielectric properties: ε r = 9.94 ± 0.01, Qf = 60 877 ± 743 GHz ( Q = 6083 ± 76, f 0 = 9.55 GHz), τ f = −5.47 ± 0.36 ppm/°C, demonstrating their potential for practical application. Remarkably, the calculation results of the P–V–L theory and density functional theory revealed that the Sb–O bond played a dominant role in affecting Qf value. These findings provide valuable insights into the development of high‐performance Li 3 Mg 2 SbO 6 and related materials.