A novel low-loss microwave dielectric using (Ca0.8Sr0.2)TiO3-modified (Mg0.95Co0.05)2TiO4 ceramics

Dielectric properties of B2O3-doped 0.92(Mg0.95Co0.05)2TiO4–0.08(Ca0.8Sr0.2)TiO3 ceramics for microwave applications

“…The grain growth of 92MCT-8CST crystallites was enhanced with increasing sintering temperature. Compared to the microstructure of pure 92MCT-8CST at 1200 • C [18], the B 2 O 3 -doped one also has a similar grain size but shows a well-developed microstructure. It is owing to the fact that the sintering aid promoted the densification of ceramic but inhibited the grain growth due to a higher surface energy.…”

“…Dielectrics such as CaTiO 3 , SrTiO 3 and (Ca 0.8 Sr 0.2 )TiO 3 (ε r ∼ 181, Q × f value ∼8300 GHz and f value ∼991 ppm/ • C) [14] have been individually employed as an effective f compensator for materials having positive f , such as MgTiO 3 , Mg 2 TiO 4 , La(Zn 1/2 Ti 1/2 )O 3 and Ca(Mg 1/3 Nb 2/3 )O 3 [8,[15][16][17]. In our previous report, 0.92(Mg 0.95 Co 0.05 ) 2 TiO 4 -0.08(Ca 0.8 Sr 0.2 )TiO 3 ceramic could possess a good combination of dielectric properties (ε r ∼ 19.22, Q × f value ∼123,200 GHz (at 9.2 GHz) and f ∼ 2.8 ppm/ • C) [18]. However, it required a high sintering temperature of 1300 • C. The chemical processing and the use of small particles of starting materials normally can reduce the sintering temperature of dielectric materials.…”

Microstructure and microwave dielectric properties of xSm(Mg0.5Ti0.5)O3–(1 − x)Ca0.8Sr0.2TiO3 ceramics

“…0.5La(Mg 0.5 Ti 0.5 )O 3 -0.5Ca 0.8 Sr 0.2 TiO 3 material showed good microwave dielectric properties: e r * 47.12, Q 9 f * 35,000 GHz, and s f * -4.7 ppm/°C [8]. A dielectric constant e r of 19.22, a Q 9 f value of 123,200 GHz and a s f value of 2.8 ppm/°C were obtained for 0.92(Mg 0.95 Co 0.05 ) 2 TiO 4 -0.08Ca 0.8 Sr 0.2 TiO 3 ceramics [17]. Therefore, xSm(Mg 0.5 Ti 0.5 )O 3 -(1 -x)Ca 0.8 Sr 0.2 TiO 3 system is likely to yield a temperature stable material.…”

Microwave Dielectric Properties of (1 − x)(Mg0.95Ni0.05)TiO3–x(Ca0.8Sr0.2)TiO3 Ceramic System With Near‐Zero Temperature Coefficient

“…Zero τ f value (temperature coefficient of resonant frequency) is also one of the major requirements for dielectric materials to allow a frequency‐stable passive component. The most convenient and promising way to achieve a zero τ f value is to combine two compounds having negative and positive τ f values to form a solid solution or mixed phases . However, high dielectric constant materials, in general, exhibit high dielectric loss (low Q × f value) and large positive τ f value, whereas low loss ceramics are usually accompanied by low ε r value and negative τ f value .…”