Structure and Dielectric Properties of Rare-Earth (La, Nd, Dy, Er) Substituted Ag(Nb, Ta)O3 Ceramics

(Ag(1-y)Ln(y))(Nb0.6Ta0.4)O3+y (Ln = La, Nd, Dy, Er) ceramics were fabricated by the conventional solid- state reaction method. The microstructures, phase structures, and dielectric properties of the ceramics were investigated. The distortion of lattice was characterized by X-ray diffractometer. The grain sizes of rare-earth substituted ceramics were smaller than those of the pure sample. These results indicated that the rare-earth ions with various ionic radii entered the unit cell of the polycrystal, and inhibited the grain growth. Low dielectric loss was obtained due to the dense microstructure. Dependence of capacitance and dielectric loss on frequency illustrated the presence of polarization mechanism.