Compositional Dependence of Structure and Dielectric Properties in Ba(ZrxTi1 - x)O3 Thin Films Grown by Pulsed Laser Deposition

Ba(Zr x Ti 1− x )O 3 (BZT) thin films with various compositions (x = 0.20, 0.25, 0.30, 0.35) were epitaxially grown on (LaAlO 3 ) 0.3 (Sr 2 AlTaO 6 ) 0.35 [LSAT] (001) single crystal substrates using pulsed laser deposition. By x-ray diffraction measurements it was found that all the films exhibited a tetragonally distorted lattice structure, which is different from that of the constituent ceramics. Consequently, an upward shifted Curie temperature was observed in each of the films. The in-plane dielectric properties were determined. At room temperature, a large dielectric tunabilities of 50% (at 500 MHz) was achieved at x = 0.30, showing its potential for use in tunable microwave devices.