Phase evolution, structure and microwave dielectric properties of Li2+xMg3SnO6 (x = 0.00-0.12) ceramics

In this study, the Li2+xMg3SnO6 (LxMS) ceramic systems were prepared by solid-state reaction using novel atmosphere-controlled sintering (x = 0.00-0.12). The influences of extra lithium contents on the phase evolution, crystal structure and microwave dielectric properties of Li2+xMg3SnO6 (LxMS) ceramics were systematically investigated. As samples were calcined from 800 to 1000 °C, the Li2Mg3SnO6 phase was formed from the chemical reaction between Li2SnO3 and MgO phase. Pure Li2Mg3SnO6 phase could be observed for samples calcined at 1000-1100 °C. But when it was exposed to high temperature air over 1100 °C, the Li2Mg3SnO6 decomposed into Mg2SnO4, MgO and Li2O. Because of the protective atmosphere and extra lithium, the εr, Q×f and τf were significantly improved by the suppression of secondary phase and pores for 0.00≤x≤0.08. However, comprehensive microwave characteristics were deteriorated for 0.08