Structural and dielectric properties of (Ba_xMg_1−x)(Ti_0.95Sn_0.05)O₃ (x = 0.025, 0.05, 0.075 and 0.1) solid solutions

The structural and dielectric properties of novel (Ba_xMg_1−x)(Ti_0.95Sn_0.05)O₃ (x = 0.025, 0.05, 0.075, 0.1) solid solutions synthesized by conventional mixed oxide route were investigated. X-ray diffraction, scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) revealed the formation of multiphase system with MgTiO₃ as main phase. The dielectric properties of these materials were strongly dependent upon amount of x concentration and it was observed that with an increase in the x concentration from 0.025 to 0.1, the relative permittivity (ɛ_r) increased from 18.0 to 22.72, losses (tan δ) increased from 0.002 to 0.025 and temperature coefficient of resonant frequency (τ_f) shifted from − 35.5 ppm/°C to + 2.8 ppm/°C. A reasonably good combination of dielectric properties was observed for (Ba_xMg_1−x)(Ti_0.95Sn_0.05)O₃ with x = 0.05, having ɛ_r of 19.7, tan δ of 0.008 and τ_f of − 13.1 ppm/°C at a sintering temperature of 1250 °C. Owing to low-to-medium relative permittivity, low losses and small negative value of temperature coefficient of resonant frequency, the present materials could be used as substrate for various communication devices including dielectric resonator antennas, filters etc.