Abstract: MgTiO₃ ceramics were prepared by MgO and TiO₂ with Al₂O₃ added, the sintering, microwave dielectric
properties and phases were investigated. XRD shows that there are two phases in MgTiO₃ ceramics without Al₂O₃ added: MgTiO₃ phase and
MgTi₂O₅ phase; besides these phases, MgAl₂O₄ phase appears after Al₂O₃ added, because of the solid phase reaction between MgO and TiO₂. Although the
MgAl₂O₄ phase impedes sintering and decreases the density, it decrease the the dielectric constant and the dielectric loss.

Key words: ceramics: dielectric constant, dielectric loss