Microwave properties of B₂O₃-doped Nd(Mg _{1 / 2}Ti_{1 / 2})O₃-CaTiO₃ dielectric resonators at microwave frequency

The effects of B₂O₃ addition on the microwave dielectric properties and the microstructures of (1 - x)CaTiO ₃-xNd(Mg_{1 / 2}Ti_{1 / 2})O₃ ceramics prepared by conventional solid-state routes have been investigated. Doping with 0.5 wt.% B₂O₃ can effectively promote the densification and the microwave dielectric properties of (1 - x)CaTiO₃-xNd(Mg _{1 / 2}Ti_{1 / 2})O₃. It is found that CaTiO ₃-Nd(Mg_{1 / 2}Ti_{1 / 2})O₃ ceramics can be sintered at 1300 °C due to the liquid phase effect of a B ₂O₃ addition observed by scanning electronic microscopy (SEM). The system forms a solid solution throughout the entire compositional range. The dielectric constant decreases from 143 to 27 as x varies from 0.1 to 1.0. In the (1 - x)CaTiO₃-xNd(Mg_{1 / 2}Ti _{1 / 2})O₃ system, the microwave dielectric properties can be effectively controlled by varying the x value. The microwave dielectric properties indicate the possibility of a phase transformation for x between 0.3 and 0.5.