Growth and characterization of epitaxial Ba(Zn1/3Ta2/3)O3 (100) thin films

We have synthesized and characterized epitaxial and stoichiometric Ba(Zn1/3Ta2/3)O3 (1 0 0) dielectric thin films grown on MgO (1 0 0) substrates by pulsed laser deposition. Advanced electronic structure calculations were used to guide the interpretation of the experimental data. Zn-enriched targets and high oxygen pressures were used to compensate for Zn loss during film growth. The Ba(Zn1/3Ta2/3)O3 films had an indirect optical band gap of ∼3.0 eV and a refractive index of 1.91 in the visible spectral range. Zn–Ta B-site ordering was not observed in the Ba(Zn1/3Ta2/3)O3 thin film X-ray diffraction data. A dielectric constant of 25 and dissipation factor of 0.0025 at 100 kHz were measured using the interdigital capacitor method. The Ba(Zn1/3Ta2/3)O3 films exhibited a small thermally activated ohmic leakage current at high fields (<250 kV cm–1) and high temperatures (<200 °C) with an activation energy of 0.85 eV.