Dielectric properties of disordered A₆B₂O₁₇ (A = Zr; B = Nb, Ta) phases

We report on the structure and dielectric properties of ternary A₆B₂O₁₇ (A = Zr; B = Nb, Ta) thin films and ceramics. Thin films are produced via sputter deposition from dense, phase-homogenous bulk ceramic targets, which are synthesized through a reactive sintering process at 1500°C. Crystal structure, microstructure, chemistry, and dielectric properties are characterized by X-ray diffraction and reflectivity, atomic force microscopy, X-ray photoelectron spectroscopy, and capacitance analysis, respectively. We observe relative permittivities approaching 60 and loss tangents <1 × 10⁻² across the 10³–10⁵ Hz frequency range in the Zr₆Nb₂O₁₇ and Zr₆Ta₂O₁₇ phases. These observations create an opportunity space for this novel class of disordered oxide electroceramics.