The rock salt oxide Li2MgTiO4: Type I dielectric and ionic conductor

The exploration of the Li–Ti–Mg–O system, using both sol–gel technique and solid state reaction method, allowed a new phase, Li2MgTiO4, with disordered rock salt structure (a = 4.159 Å) to be synthesized. The latter is shown to be a good type I dielectric material, with a relative constant of 15 at high frequency and low dielectric loss (tanδ < 10−3) over the temperature range −60 to 160 °C. It is also observed that the sintering temperature of this phase is strongly lowered by adopting the sol–gel technique compared to solid state reaction (1150 °C instead of 1300 °C). Finally we show that this phase exhibits cationic conductivity above 400 °C (σ600 °C = 9 × 10−5 S cm−1).