Dramatic impact of raw chemicals on the electrical properties of SrTiO₃ ceramics

The dielectric loss (tan δ) value of stoichiometric SrTiO₃ (ST), prepared using the solid-state reaction method, exhibits a random variation between 0.0006 and 0.01968 at room temperature and a frequency of 1 kHz in the literature. This variability makes it challenging to obtain reliable and reproducible performance for ST-based devices, especially when the underlying reasons are not yet completely understood. This work reports the significant effects of different raw materials, with various forms of TiO₂, on the dielectric and electrical properties of ST ceramics. The results show that the purity of SrCO₃ and TiO₂ ultimately leads to distinct differences in dielectric properties, impedance properties, activation energy across the ST ceramics. Crystal comparison demonstrates that anatase TiO₂ is more suitable for dielectric applications. These results provide a reasonable explanation for the large variations in reported ST properties in the literature, which emphasizes the critical importance of selecting suitable reagents in ST-based ceramics. This insight opens up a new avenue for design optimization and highlights the promising potential of ST-based ceramics.