Sol-gel synthesis and dielectric properties of Ruddlesden-Popper phase Sr_(n+1)Ti_nO_(3n+1) (n=l, 2, 3, ∞)

摘要

A series of high purity Ruddlesden-Popper phase Sr_(n+1)Ti_nO_(3n+1) (n=l, 2, 3, oo) nanoscale powders have been produced by the sol-ge) method. The final sintering temperatures of SrTiO_3, Sr_4Ti_3O_(10), Sr_3Ti_2O_7 and Sr_2TiO_4 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 SrTiO_3, Sr_4Ti_3O_(10), Sr_3Ti_2O_7 and Sr_2TiO_4 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.