Dielectric properties of (100)-oriented Ba(Zr, Ti)O3/La0.7Ca0.3MnO3 heterostructure thin films prepared by pulsed laser deposition

Highly (100)-oriented Ba(Zr0.2Ti0.8)O3/La0.7Ca0.3MnO3 (BZT/LCMO) heterostructure thin films have been grown on Si(100) and Pt(111)/Ti/SiO2/Si(100) substrates prepared by pulsed laser deposition. The structure and surface morphology of the films have been characterized by x-ray diffraction and atomic force microscopy. The dielectric constant of the films changes significantly with applied dc bias field and the films have high tuneability of 59.1%, 52% and 59.4% at an applied field of 400 kV cm−1, respectively, for the BZT film on Pt/Ti/SiO2/Si and the BZT/LCMO heterostructure films on Si and Pt/Ti/SiO2/Si substrates. The tuneability of the BZT/LCMO thin films on Pt-coated Si substrate was higher than that of the BZT thin films on Pt/Ti/SiO2/Si and LCMO/Si substrates. The high tuneability has been attributed to the (100) texture of the films and larger grain sizes. The BZT thin film is an attractive candidate for tuneable microwave device applications.