Study on the dielectric properties of Mg-doped NaBiTi ceramics**Project supported by the Fund from the Hubei Provincial Department of Education, China (Grant No. D20161006).

Abstract

With the interest in using lead-free materials to replace lead-containing materials increasing, the use of NaBiTiO (NBT) has come into our sight. We studied the composition of NBT and found that NaBiTiO ceramics can be compositionally tuned by Mg-doping on the Ti-site to optimize the dielectric properties. In this study, Mg-doped NaBiTiO (NaBi(TiMgO) ceramics were prepared by a conventional mixed oxide route at different sintering temperatures, and their dielectric properties have been studied at a wide temperature range. X-ray diffraction (XRD) patterns of the NBT-based ceramics indicate that all samples have a pure phase without any secondary impurity phase. The experimental data show that after Mg-doping, the relative permittivity and dielectric loss become lower at 1040, 1060, and 1080 °C except 1020 °C and at different frequencies from 10 kHz, 100 kHz to 1 MHz. Take 1060 °C for example, when the sintering temperature is 1060 °C at 1 MHz, the minimum relative permittivity of NaBiTiO is 32.9 and the minimum dielectric loss is 0.01417, the relative permittivity of NaBi(TiMgO under the same condition is 25.8 and the dielectric loss is 0.000104. We explored the mechanism of Mg-doping and surprisingly found that the dielectric property of NaBi(TiMgO becomes better owing to Mg-doping. Thus, NaBi(TiMgO can be used in microwave ceramics and applied to new energy materials.