Low loss Sr1−xCaxLa4Ti5O17 microwave dielectric ceramics

Structural phase transition and microwave dielectric properties of Ca1−x Sr x TiO3 (x = 0.1–0.9) ceramics

“…The idea of using a solid state dielectric material as a resonator in wireless telecommunication devices, satellite broadcasting equipment and mobiles handsets, was first floated by Richtmyer in 1939 [1]. The suitability of a material to be used in microwave dielectric resonators depends on three important characteristics.…”

Raman spectroscopy and microwave dielectric properties of Sn substituted SrLa4Ti5O17 ceramics

“…ε r = 57, Q u f o = 15,000 GHz, and τ f = −8.16 ppm/°C were obtained for Ca 0.99 Zn 0.01 La 4 Ti 5 O 17 ceramics with 0.5 wt.% CuO additive that were sintered at 1450°C for 4 h [5]. On the other hand, SrLa 4 Ti 5 O 17 was reported to have ε r = 61, Q u f o = 9969 GHz and τ f = 117 ppm/°C [3]. The high positive τ f precluded its use as dielectrically loaded antenna.…”

Phase evolution and microwave dielectric properties of A5M5O17-type ceramics

“…Perovskites and perovskite-related structures have the flexibility to accommodate a variety of substitutions either at the A and/or B-site of the perovskite unit cell which enables tailoring of their properties for a wide range of applications. Among these, SrLa 4 Ti 5 O 17 has been reported to crystallize into an orthorhombic (Pnnm) structure with lattice parameters a = 5.549(5)Å, b = 31.299(9)Å, c = 3.9104(3)Å and r = 60.8, τ f = 117 ppm/°C and Q × f o = 9969 GHz [9]. Consequently, the effect of partial substitution of Ca for Sr on the dielectric properties of Sr 1−x Ca x La 4 Ti 5 O 17 series has been investigated in an attempt to tune its τ f through zero and improve the quality factor [9].…”

“…Among these, SrLa 4 Ti 5 O 17 has been reported to crystallize into an orthorhombic (Pnnm) structure with lattice parameters a = 5.549(5)Å, b = 31.299(9)Å, c = 3.9104(3)Å and r = 60.8, τ f = 117 ppm/°C and Q × f o = 9969 GHz [9]. Consequently, the effect of partial substitution of Ca for Sr on the dielectric properties of Sr 1−x Ca x La 4 Ti 5 O 17 series has been investigated in an attempt to tune its τ f through zero and improve the quality factor [9]. This study revealed substantial improvement in τ f from 117 ppm/°C to −1.4 pm/°C and Q × f o from 9969 GHz to 11,432 GHz along with a small decrease in r from 60.8 to 53.7.…”