Studies of phase transitions, Raman spectra and microwave dielectric properties of perovskite-structured (Na1−xLix)0.5Nd0.5TiO3 ceramics

High dielectric constant microwave ceramics are essential for ceramic-based devices, such as the dielectric resonator used in miniaturized mobile phone components. Herein, perovskite-type (Na_1−xLi_x)_0.5Nd_0.5TiO₃ (0 ≤ x ≤ 1) ceramics were fabricated using the traditional solid-state processing to explore the changing mechanism of dielectric properties and obtain a component with favorable microwave dielectric properties. The results showed that the maximum ε_r value (140.3) of samples achieved at x = 0.4 due to changes in bond valence at the B-site, while Q×f and τ_f values decreased with increasing x value. Raman spectra demonstrated that the broader Raman scattering peaks corresponded to shorter microwave energy propagation decay times, which resulted in a decline of Q×f value. The (Na_0.3Li_0.7)_0.5Nd_0.5TiO₃ sample showed promising microwave dielectric properties (ɛ_r = 127.3, Q×f = 2,471 GHz, and τ_f = − 47.3 ppm/°C). Finally, it was determined that a temperature-stable ceramic with a high ε_r value could be produced when the x value fell within the range of 0.7 to 0.8.