A novel high-Q oxyfluoride Li4Mg2NbO6F microwave dielectric ceramic with low sintering temperature

Sintering behavior, crystal structure, and microwave dielectric properties of a novel NaY9Si6O26 ceramic

“…This can be ascribed to the relatively lower ionic polarizability of Na + ( α = 1.80 Å 3 ), Y 3+ ( α = 3.81 Å 3 ), and Si 4+ ( α = 0.87 Å 3 ) 27 . For a given chemical formula, the theoretical ε r value ( ε r(theo) ) is associated with the unit cell volume ( V m ) and molecular ion polarizability ( α D ), following this relationship 28 : $$$$\begin{equation}{\varepsilon _{r\left( {theo} \right)}} = \frac{{3{V_m} + {\mathrm{8}}\pi {\alpha _D}}}{{3{V_m} - {\mathrm{4}}\pi {\alpha _D}}}\end{equation}$$$$…”

Ceramic compositions for 5G devices containing niobium: A survey

“…The specimens were sintered in the 850−950 • C range. The relative density achieved high values (≥ 97.5%) at 900 • C. The optimal microwave dielectric properties were obtained after sintering at 900 • C: ε r ∼15.53, Qxf = 93 300 GHz, and τ f ∼ −39.8 ppm/ • C. 55 Li 6 MgTiNb 1-x V x O 8 F (0 ≤ x ≤ 0.08)…”

“…The relative density achieved high values (≥ 97.5%) at 900°C. The optimal microwave dielectric properties were obtained after sintering at 900°C: ε r ∼15.53, Qxf = 93 300 GHz, and τ f ∼ −39.8 ppm/°C 55 …”

Microwave Dielectric Properties of Li3TiO3F Oxyfluorides Ceramics

“…For example, in 2019 the structure and microwave dielectric performances of novel Ti-containg oxyfluorides, such as Li 7 Ti 3 O 9 F and Li 5 Ti 2 O 6 F were first reported by Fang et al [10,11]. Subsequently, several binary, ternary, and multicomponent Nb-containing oxyfluorides with promising microwave dielectric performances, such as Li 5.5 Nb 1.5 O 6 F, Li 4 Mg 2 NbO 6 F, and Li 7 (Nb 1−x Ti x)2 O 8−x F, Li 6 MgTiNb 1−x V x O 8 F, have been reported by Liu et al [13][14][15]. In 2023, Zhang et al reported a new oxyfluoride dielectric ceramic system of Li 2+x ZrO 3 F x , among which the Li 3 ZrO 3 F ceramics simultaneously exhibited a near zero τ ƒ (1.2 ppm/ • C), a high Q × f (65,100 GHz), and a low firing temperature (925 • C) [16].…”