Effects of film thickness and preferred orientation on the dielectric properties of (Bi1.5Zn0.5)(Zn0.5Nb1.5)O7 films

Bi1.5Zn0.5)(Zn0.5Nb1.5) O-7 (BZN) films with different thicknesses and preferred orientations have been fabricated on Nb doped SrTiO3 substrates by pulsed laser deposition. As the thickness increases, the permittivity increases, and the dielectric loss decreases, while the tunability only has a little variation. The asymmetric behaviour of the electric field dependent permittivity reduces gradually with the increasing thickness, which should be attributed to the decrease in the effect of the interfacial layer between the dielectric film and substrate ( electrode). Furthermore, compared with the (1 0 0) oriented BZN film, BZN film with (1 1 1) preferred orientation exhibits high dielectric loss.