Effect of heat treatment on structure evolution and properties of nano zinc titanate ceramics

Nano zinc titanate ceramics are prepared using a conventional solid state method. The obtained compacts are sintered at 800, 900, 1000 and 1100 °C for 3 h. The prepared compacts are analyzed using X‐ray diffraction (XRD) and scanning electron microscopy (SEM) for structural and microstructural studies. Based on the X‐ray diffraction (XRD) data, it is observed the coexistence of ZnTiO₃ and α‐Zn₂TiO₄ phases together at low temperature (800 °C) without the presence of TiO₂ (rutile) contradicting the general mechanism stating the transformation of ZnTiO₃ to α‐Zn₂TiO₄ and TiO₂ at higher temperatures. A new mechanism is proposed to explain the formation of nano ZnTiO₃ and α‐Zn₂TiO₄ structures depending on the role of TiO₂ in achieving this mission. According to this mechanism, we propose a partial diffusion of TiO₂ in the ZnO lattice forming the ZnTiO₃ phase. The second part of TiO₂ acts as a catalyst that facilitates the transformation of nano ZnTiO₃ to nano α‐Zn₂TiO₄. The catalytic power of rutile is achieved from its enhanced tensile stress that induces the phase transition from nano ZnTiO₃ to nano α‐Zn₂TiO₄.