Dielectric properties of columnar-grained (Ba0.75Sr0.25)(Zr0.25Ti 0.75)O3 thin films prepared by pulsed laser deposition

The preferentially (1 0 0)-oriented (Ba0.75Sr0.25)(Zr0.25Ti0.75)O3 (BSZT) thin films were deposited on Pt(1 1 1)/Ti/SiO2/Si(1 0 0) substrates by a pulsed laser deposition process. The films exhibited columnar-grained characteristics with grain sizes of 30-80 nm.The temperature dependence of dielectric constants was investigated; it is shown that the cubic to rhombohedral phase transition temperature is located at the vicinity of 200 K. At 300 K and 1 MHz, the dielectric constant and loss tan δ are 321 and 0.014, respectively. The dielectric constant of BSZT film changes significantly with applied DC bias field and has a high tunability of ∼53% at 1 MHz and an applied field of 600 kV/cm.