Structural Characteristics and Microwave Dielectric Properties of (Al0.5B0.5)xTi1-xO2 (B=Nb5+, Sb5+, Ta5+) Solid Solutions

Effects of structural characteristics on the dielectric properties of (Al 0.5 B 0.5 ) x Ti 1 − x O 2 (B = Nb 5 + , Sb 5 + , Ta 5 + , 0.2 ≤ x ≤ 0.5) ceramics were investigated at microwave frequency. The sintered specimens show the solid solutions with the tetragonal rutile structure through the entire composition range. With the increase of (Al 0.5 B 0.5 )O 2 content, the ratio of apical bond (dapical) to equatorial bond(dequatorial) decreases by the change of cations bond valence. The dielectric constant (K) and temperature coefficient of resonant frequency (TCF) reduce also with (Al 0.5 B 0.5 )O 2 content. These results could be attributed to the changes of bond length ratio and the distortion of oxygen octahedra, respectively. The quality factor is dependent on the grain size of the sintered specimens.