Structural analysis and microwave dielectric properties of a novel Li2Mg2Mo3O12 ceramic with ultra-low sintering temperature

Abstract

A single orthorhombic phase Li2Mg2Mo3O12 ceramic as a novel ultra-low sintering temperature ceramic was investigated and synthesized using a solid-state method. The best sintering temperature was 650 °C, with a high relative density of 97.86%. The structure of the Li2Mg2Mo3O12 ceramic was characterized by Rietveld refinement, XPS, Raman spectroscopy and FT-IR analysis. The Rietveld refinement and XPS results demonstrated that Mo6+ is located in the near-ideal MoO4 tetrahedrons, and Mg2+ and Li+ are distributed in the centre of three kinds of AO6 polyhedrons. The Raman and FT-IR studies confirmed the internal vibrational features of the Li2Mg2Mo3O12 ceramic. The correlations between the structural and microwave dielectric losses of the Li2Mg2Mo3O12 ceramic were analysed by Raman spectroscopy. The lower FWHM of the Raman peak indicated lower intrinsic dielectric loss. The Li2Mg2Mo3O12 ceramic exhibited an optimal microwave dielectric property when sintered at 650 °C: εr = 9.26, Q × f = 58,583 GHz, and τf = −51 ppm/°C. Li2Mg2Mo3O12 ceramic may become a potential material for ULTCC applications.