Sol–gel synthesis and dielectric properties of Ruddlesden–Popper phase Srn+1TinO3n+1 (n=1, 2, 3, ∞)

A series of high purity Ruddlesden–Popper phase Srn+1TinO3n+1 (n=1, 2, 3, ∞) nanoscale powders have been produced by the sol–gel method. The final sintering temperatures of SrTiO3, Sr4Ti3O10, Sr3Ti2O7 and Sr2TiO4 determined by TG-DSC analysis were 800 °C, 950 °C, 1050 °C and 1050 °C, respectively. The single phase structures of the four powders were identified by X-ray diffraction analysis. The different molecular structures and the different vibration bands were studied by Fourier transform infrared absorption spectroscopy and Raman spectroscopy. The dielectric constants of SrTiO3, Sr4Ti3O10, Sr3Ti2O7 and Sr2TiO4 were measured to be 114, 55, 41 and 30, respectively, at 100 kHz. The dielectric losses of the four materials were found to be lower than 4×10−2 above 100 kHz.