Ferroelectric and dielectric properties of sol-gel derived BaxSr1-xTiO3 thin films

Ferroelectric thin films of Ba0.7Sr0.3TiO3, Ba0.8Sr0.2TiO3, Ba0.9Sr0.1TiO3 and BaTiO3 were fabricated by a modified sol-gel technique on Pt/Ti/SiO2/Si substrates. All the compositions crystallized in perovskite structure and consist of well-defined grains. As the value of x increases grain size of the BaxSr1-xTiO3 thin films increases while the dielectric permittivity decreases. Ba0.7Sr0.3TiO3 composition possesses the highest dielectric permittivity of 748 (at 100 kHz). Hysteresis loops measured at room temperature for all compositions showed that BaTiO3 has the largest remnant polarization of 4.8 *mC/cm2. The dielectric and ferroelectric properties of the sol-gel derived BaxSr1-xTiO3 thin films are strongly dependent on the Sr content and the grain size