Li+ enrichment to improve the microwave dielectric properties of Li2ZnTi3O8 ceramics and the relationship between structure and properties

Herein, Li + -enriched Li (1+ x )2 ZnTi 3 O 8 ceramics are prepared via the solid-phase methods. As x increases, the unit cell volume gradually increases, while the grain size initially increases and then decreases gradually. The Li (1+0.06)2 ZnTi 3 O 8 ceramics exhibit the best dielectric properties : ε r = 25.92, Q × f = 109534 GHz (@7.37 GHz, which is a 48 % increase compared with the stoichiometric counterpart.), and τ f = −8.21 ppm/°C. The complex chemical bond theory and Raman spectroscopy reveal that Ti-O bonds have a significant effect on the dielectric properties . An optimal Li + enrichment leads to an overall reduction in the distortion of the Li/ZnO 4 tetrahedra, resulting in a reduction in τ f . First-principles calculations demonstrate that a suitable excess of Li + leads to an increase in the band-gap as well as an enhanced electron cloud density in the internal space of the Li1/ZnO 4 tetrahedra, thereby increasing the Q × f . In summary, Li + -enriched Li (1+0.06)2 ZnTi 3 O 8 ceramics are promising for a wide array of applications in microwave communications.