Effects of structural characteristics on microwave dielectric properties of (1 − x)Ca0.85Nd0.1TiO3–xLnAlO3 (Ln = Sm, Er and Dy) ceramics

Dependence of microwave dielectric properties on the structural characteristics of (1 − x)Ca0.85Nd0.1TiO3–xLnAlO3 (Ln = Sm, Dy and Er) ceramics were investigated as a function of LnAlO3 content (0.05 ≤ x ≤ 0.25). For the specimens with SmAlO3, a single phase with orthorhombic perovskite was obtained through the entire composition, however, Dy2Ti2O7 and Er2Ti2O7 were detected as a secondary phase along with the orthorhombic perovskite phase for the specimens with DyAlO3 (x = 0.25) and ErAlO3 (0.10 ≤ x ≤ 0.25), respectively. With an increase of LnAlO3 content, the dielectric constant decreased due to the smaller ionic polarizability of LnAlO3 than Ca0.85Nd0.1TiO3. The temperature coefficient of the resonant frequency (TCF) decreased with LnAlO3 content resulted from an increase of oxygen octahedral distortion.