The structure and dielectric properties of an anodic oxide on Nb solid solution (Nb-ss)/Nb2N two phase alloys were investigated The anodized specimens were covered with two types of anodic oxides on the Nbss and Nb2N phases respectively The relative permittivity and leakage current density of the anodized specimens can be explained by the combination of the two oxides the relative permittivity of the specimens increased with the volume fraction of the oxide on the Nb phase because the relative permittivity of the oxide on the Nbss phase is higher than that on the Nb2N phase The leakage current was suppressed irrespective of the constitute phases as compared with the anodized pure Nb because it was reduced in both the oxides on the Nb-ss and Nb2N phases (c) 2010 Elsevier B V All rights reserved