OCCURRENCE OF DIELECTRIC 1-1-4 COMPOUND IN THE TERNARY-SYSTEM BAO-LN2O3-TIO2 (LN = LA, ND, AND SM) .2. REEXAMINATION OF FORMATION OF ISOSTRUCTURAL TERNARY COMPOUNDS IN IDENTICAL SYSTEMS

To establish the correct composition of a ternary compound having higher TiO2 content in the BaO-Nd2O3-TiO2 system, the phase change of samples with variable controlled compositions, which were prepared by a modified coprecipitation method, was examined by X-ray diffractometry and Raman spectroscopy. Identification of the phases present in the calcined samples and microstructural evidence for the fired product from electron microprobe analysis clearly indicated that the ternary compound having the composition 1:1:4 occurs in the present system. X-ray powder diffraction data of the isostructural 1:1:4 and 1:1:3 compounds in each identical ternary system (Ln = La, Nd, and Sm) were refined and indexed. Partial subsolidus phase relations consisting of different composition triangles were also proposed for the present ternary systems.