Structure, dielectric, ferroelectric, and optical properties of (1−x)Ba(Zr0.2Ti0.8)O3−x(Ba0.7Ca0.3)TiO3 thin films prepared by sol–gel method

Abstract We report high dielectric tunabilities of (1 − x)Ba(Zr 0.2 Ti 0.8 )O 3 − x(Ba 0.7 Ca 0.3 )TiO 3 (BZT–xBCT) (x = 0.15, 0.30, 0.40, 0.45, 0.50, and 0.55) thin films prepared by a sol–gel method. The films show a pure perovskite structure with random orientation. They have moderate dielectric constant ranging from 350 to 500 and low dielectric loss near 3.0% at 1 kHz with 0 V bias at room temperature. The dielectric tunability of the BZT–0.55BCT thin films is up to 65% at 400 kV/cm and 100 kHz. The films exhibit a high optical transmission in the range of 420 nm–1500 nm. Their optical band gap energies are about 3.90 eV.