Preparation, characterization and dielectric properties of Ba5LnZnTa9O30 (Ln=La, Sm) ceramics

Abstract Ba 5 LnZnTa 9 O 30 (Ln=La, Sm) ceramics were prepared by high temperature solid-state reaction route. The samples were characterized by X-ray diffraction, scanning electron microscopy (SEM), and differential scanning calorimetry (DSC) methods. They belong to paraelectric phase of filled tetragonal TB structure at room temperature with unit cell a =12.5909(4) A, c =3.9622(2) A for Ba 5 LaZnTa 9 O 30 ; and a =12.5777(4) A, c =3.9544(2) A for Ba 5 SmZnTa 9 O 30 . At 1 MHz, Ba 5 LaZnTa 9 O 30 has high dielectric constants of 89 with low dielectric loss 0.0067, and temperature coefficients of the dielectric constant ( τ e ) −811 ppm °C −1 ; Ba 5 LaZnTa 9 O 30 has dielectric constants of 74 with low dielectric loss 0.0035, and τ e −474 ppm °C −1 .