Synthesis, crystal structure and low loss of Li3Mg2NbO6 ceramics by reaction sintering process

Abstract

Abstract An investigation into an effective and simple process for the production of a low-cost material with high production efficiency has resulted in a significant impact on commercial production. In the present work, we synthesized the low loss Li 3 Mg 2 NbO 6 ceramic using an effective and simple reaction sintering process. A single orthorhombic phase was corroborated by XRD and Rietveld refinement. The packing fraction and Nb-O bond valence were determined according to the Rietveld refinement results to explore the relationship between the structure and microwave dielectric performance. The Raman analysis indicated that the shift of the band near 772 cm -1 assigned to the Mg-O bond vibration was consistent with the diversification of the cell volume. Furthermore, dense and homogeneous microstructures with large grain sizes (∼130 μm) were obtained when sintered at 1350 °C. The relative density exerted an influence on the dielectric constant, while the packing fraction and grain size influenced the Q × f value of the Li 3 Mg 2 NbO 6 ceramics. Moreover, the Nb-O bond valence dominated the τ f value of the Li 3 Mg 2 NbO 6 ceramics. Excellent microwave dielectric characteristics for the samples sintered at 1350 °C: e r = 14.5, Q × f = 116,000 (9.76 GHz) GHz and τ f = −24.5 ppm/°C were achieved by the reaction sintering process, exhibiting a potential for industrial production.