The effects of inequivalent La3+ introduction on the structure and dielectric properties of SrTiO3 ceramic at microwave range

Inequivalent La 3+ is firstly utilized to modify the microwave dielectric properties in SrTiO 3 ceramic system. For the general composition of Sr 1-x La 2x/3 TiO 3 (0 ≤ x ≤ 1), the effects of La 3+ introduction on the phase transition and structural changes are systematically investigated. The correlation between A-site ordering degree and dielectric loss in microwave range is established, and the temperature coefficient of resonant frequency is also dramatically improved. When x = 0.945, excellent dielectric properties of ε r ∼89.3, Qf ∼15243 GHz (@4.3 GHz) and τ f  ∼ 160 ppm/°C are obtained, making it potential to meet the application requirements of 5G technologies.