Dielectric relaxation and microwave dielectric properties of low temperature sintering LiMnPO4 ceramics

LiMnPO4 with olivine structure is usually widely studied as a promising cathode material for lithium batteries. In present work, LiMnPO4 ceramic has been found to have potential application on low-temperature co-fired ceramic technology. Single phase of LiMnPO4 was synthesized by one-step solid state reaction using ammonium polyphosphate (APP) as PO4 precursor. Compatibility test shows the coexistence of LiMnPO4 and silver at 750 °C. Dense LiMnPO4 ceramic with more than 95% theory density can be obtained at 750 °C. The dielectric measurement shows the dielectric relaxation which obeys the universal law with fractional exponent. The dielectric spectra are well fitted with the equivalent circuit capacitance parallel with constant phase degree. The optimized microwave dielectric properties show low dielectric constant (8.1), and high quality factor (44,224 GHz).