Effect of electronegativity on microwave dielectric properties of MgTi 1 −x (A 1 / 3 Sb 2 / 3 ) x O 3 (A = Mg 2+ , Zn 2+ ) ceramics

Microwave dielectric properties of MgTi 1− x (A 1/3 Sb 2/3 ) x O 3 (A = Mg 2+ , Zn 2+ , 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 = Mg 2+ , Zn 2+ ) and O 2− ion. A single phase with an ilmenite structure was detected for the specimens sintered at 1450°C for 4 hours in the entire range of compositions. With the substitution of (A 1/3 Sb 2/3 ) 4+ ions (A = Mg 2+ , Zn 2+ ) at Ti 4+ ‐sites of MgTiO 3 , 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 = Mg 2+ , Zn 2+ ) and Ti 4+ ion. The specimens with (Mg 1/3 Sb 2/3 ) 4+ ions exhibited higher Qf values than those with (Zn 1/3 Sb 2/3 ) 4+ ions. These results could be attributed to the smaller electronegativity of (Mg 1/3 Sb 2/3 ) 4+ (1.80) than that of (Zn 1/3 Sb 2/3 ) 4+ (1.92). The dependences of the microwave dielectric properties on the structural characteristics of the MgTi 1− x (A 1/3 Sb 2/3 ) x O 3 ceramics were also discussed.