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

Ferroelectric thin films of Ba 0.7 Sr 0.3 TiO 3 , Ba 0.8 Sr 0.2 TiO 3 , Ba 0.9 Sr 0.1 TiO 3 and BaTiO 3 were fabricated by a modified sol-gel technique on Pt/Ti/SiO 2 /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 Ba x Sr 1-x TiO 3 thin films increases while the dielectric permittivity decreases. Ba 0.7 Sr 0.3 TiO 3 composition possesses the highest dielectric permittivity of 748 (at 100 kHz). Hysteresis loops measured at room temperature for all compositions showed that BaTiO 3 has the largest remnant polarization of 4.8 μC/cm 2 . The dielectric and ferroelectric properties of the sol-gel derived BaxSr 1-x TiO 3 thin films are strongly dependent on the Sr content and the grain.