The La4Ti3O12 BaLa4Ti4O15 system: structural characterization and dielectric properties

Summary A series of microphases with trigonal symmetry and general formula A n Ti n−1 O 3n (A=La,Ba) have been observed as different intergrowths of La 4 Ti 3 O 12 (n=4) and BaLa 4 Ti 4 O 15 (n=5). Perfectly ordered intergrowths labelled 4 1 5 1 , 4 2 5 1 , …, 4 6 5 1 4 P 5 Q corresponds to the intergrowth of P (n=4) structural units and Q (n=5) structural units have been characterized by X-ray diffraction and transmission electron microscopy. Dielectric measurements showed that ceramic bodies with 92% of the theoretical density showed good thermal stability of the permittivity and dielectric loss between 200 Hz and 1 MHz. Significant conductivity was observed above 750 °C.