Low‐Temperature Sintering and Microwave Dielectric Properties of Zinc Metatitanate‐Rutile Mixtures Using Boron

<jats:p> Mixtures of zinc metatitanate and rutile (ZnTiO <jats:sub>3</jats:sub> + <jats:italic>x</jats:italic> TiO <jats:sub>2</jats:sub> , where <jats:italic>x</jats:italic> = 0‐0.5) have been prepared via the conventional mixed‐oxide method. Centrifugal planetary milling with zirconia beads 1 mm in diameter produced very fine powders (mean particle size of 0.2 µm), which allowed the synthesis of ZnTiO <jats:sub>3</jats:sub> and sintering at temperatures <945°C, which is the decomposition temperature of ZnTiO <jats:sub>3</jats:sub> . Sintering of the mixtures was enhanced further by the addition of B <jats:sub>2</jats:sub> O <jats:sub>3</jats:sub> . Densities of >94% of the theoretical density have been attained for the specimens that were sintered at 875°C for 4 h with B <jats:sub>2</jats:sub> O <jats:sub>3</jats:sub> additions of <1 wt%. Microwave dielectric properties of the aforementioned compositions were as follows: dielectric constant of 29‐31, normalized quality factor of 56000‐69000 GHz, and a temperature coefficient of resonance frequency between ‐10 and +10 ppm/°C. Sintering was enhanced by the formation of a ZnO‐B <jats:sub>2</jats:sub> O <jats:sub>3</jats:sub> liquid phase, which affected the microwave properties, because of variation in the phase composition. </jats:p>