The Effect of Dopants on the Dielectric Properties of Ba(B′ 1/2 Ta 1/2 )O ₃ (B′=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Y, Yb, and In) Microwave Ceramics

Low‐loss dielectric ceramics based on Ba(B′ 1/2 Ta 1/2 )O 3 (B′=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Y, Yb, and In) complex perovskites have been prepared by the solid‐state ceramic route. The dielectric properties (ɛ r , Q u , and τ f ) of the ceramics have been measured in the frequency range 4–6 GHz by the resonance method. The resonators have a relatively high dielectric constant and high quality factor. Most of the compounds have a low coefficient of temperature variation of the resonant frequencies. The microwave dielectric properties have been improved by the addition of dopants and by solid solution formation. The solid solution Ba[(Y 1− x Pr x ) 1/2 Ta 1/2 ]O 3 has x =0.15, with ɛ r =33.2, Q u × f =51,500 GHz, and τ f ≈0. The microwave dielectric properties of Ba(B′ 1/2 Ta 1/2 )O 3 ceramics are found to depend on the tolerance factor ( t ), ionic radius, and ionization energy.