Structures and dielectric properties of Bi_1.5Zn _1.0Nb_1.5O₇ thin films prepared by pulsed laser deposition at low temperature

Amorphous Bi_1.5Zn_1.0Nb_1.5O₇ (BZN) thin films have been prepared on Pt/TiO₂/SiO ₂/Si(100) substrates by pulsed laser deposition (PLD) process at low temperature. BZN films were deposited at room temperatures under the oxygen pressure from 1 Pa to 30 Pa, and then post-annealed at the temperature below 200°C. XRD analysis indicates that BZN films are still amorphous in nature after the post-annealing. The dielectric constant of amorphous BZN films increases and the dielectric loss decreases after the post-annealing process. The dielectric properties of BZN films are strongly dependent on the oxygen pressure. BZN Thin films deposited at 1 Pa exhibit superior dielectric characteristics. Dielectric constant and loss tangent are 60.2 and 0.006 at 10 kHz, respectively. Leakage current density is less than 1 × 10 ^-7 A/cm² at 300 kV/cm.