Microwave dielectric properties of NaxNd(2-x)/3TiO3 solid solutions

Na_xNd_(2-x)/3TiO₃ solid solutions possess tetragonal or orthorhombic perovskite structure, where the A-sites are characterized by 2 kinds of cations (Na⁺, Nd³⁺) and vacancies. We have measured microwave dielectric properties of Na_xNd_(2-x)/3TiO₃ solid solutions (x = 0.05 to 0.5) to investigate an effect of the compositional ordering in the A-sites of the perovskite structure. According to powder X-ray diffraction, the A-site is disordered in the composition range of x = 0.29 to 0.5. A compositional ordering (Na⁺, vacancy / Nd^{3 +}) in Asites appeared when x = 0.05 to 0.2. The quality factor (Qmiddotf), where Q is the inverse of dielectric loss and f is frequency, was found to be slightly improved with decreasing Na content in the range of x = 0.05 to 0.2, suggesting that the Qmiddotf of the Na_xNd_(2-x)/3TiO₃ solid solutions depends on the compositional ordering in A-sites.