Ba3ZnTa2-xNbxO9 and Ba3MgT2-xNbxO9: synthesis, structural and dielectric studies

Oxides of the families Ba3ZnTa2-xNbxO9 and Ba3MgTa2-xNbxO9 were obtained by the solid state reaction route at 1573 K and were found to crystallize in the disordered (cubic) perovskite structure. In Ba3ZnTa2-xNbXO9 and Ba3MgTa 2-xNbxO9 the entire range (0 less than or equal to x less than or equal to 1) of solid solutions could be synthesized. The dielectric constant decreas es with increase in frequency for all compositions in the range 40 Hz to 10 0 kHz (epsilon (r) varies from 16 to 22). The dielectric loss (D) shows a b road maximum for both Ba3ZnTa2-xNbxO9 and Ba3MgTa2-xNbxO9. The maxima is ce ntered around 2 kHz in the former and near 10 kHz in the latter. (C) 2001 E lsevier Science Ltd. All sights reserved.