Effect of electronegativity on microwave dielectric properties of MgTi1-x(A1/3Sb2/3)xO3 (A = Mg2+, Zn2+) ceramics

Microwave dielectric properties of MgTi1-x(A(1/3)Sb(2/3))(x)O-3 (A = Mg2+, Zn2+, 0 <= x <= 0.125) ceramics were investigated as a function of the electronegativity difference (X) between (A(1/3)Sb(2/3))(4+) ions (A = Mg2+, Zn2+) and O2- ion. A single phase with an ilmenite structure was detected for the specimens sintered at 1450 degrees C for 4 hours in the entire range of compositions. With the substitution of (A(1/3)Sb(2/3))(4+) ions (A = Mg2+, Zn2+) at Ti4+-sites of MgTiO3, the quality-factor (Qf) values of the specimens increased up to x = 0.05 mol, and then decreased with the further substitution owing to the electronegativity difference (X) between the (A(1/3)Sb(2/3))(4+) ions (A = Mg2+, Zn2+) and Ti4+ ion. The specimens with (Mg1/3Sb2/3)(4+) ions exhibited higher Qf values than those with (Zn1/3Sb2/3)(4+) ions. These results could be attributed to the smaller electronegativity of (Mg1/3Sb2/3)(4+) (1.80) than that of (Zn1/3Sb2/3)(4+) (1.92). The dependences of the microwave dielectric properties on the structural characteristics of the MgTi1-x (A(1/3)Sb(2/3))(x)O-3 ceramics were also discussed.