Structure and microwave dielectric properties of La(2−x)/3NaxTiO3

The structure evolution, and microwave dielectric properties of La(2−x)/3NaxTiO3 Ceramics( $$ x = 0.02 \leqslant \times \leqslant 0.5 $$ ) were investigated in this paper. X-ray diffraction (XRD) and scanning electron microscopy (SEM) results show that all samples exhibit single phase. The concentration and ordering degree of A-site vacancies decrease with the increase of x value, and no A-site ordering exists when x > 0.2. The dielectric constant decreases with the decrease of x value. The Q × f value increases up to x = 0.1 and then decreases with the further increase of x value. A maximum Q × f value of 18,826 GHz is obtained when x = 0.06. The temperature coefficient of resonant frequency exhibits positive value and decreases greatly with the decrease of x value.