Microwave dielectric properties and microstructures of BaPr2Ti4O12 and
BaPr2Ti5O14 ceramics which have extremely similar crystal structures,
were investigated, including those of the solid solution represented
by the formula of Ba-(6-x)Pr8+2x/3Ti18O54 ceramics. It is suggested th
at BaPr2Ti5O14 ceramics are composed of mixed phases, approximately 85
.0 vol. % Ba4.05Pr9.3Ti18O54 (x = 1.95), 8.1 vol. % TiO2, and 6.9 vol.
% BaTi4O9. The microwave dielectric properties of the Ba6-xPr8+2x/3Ti
18O54 system are strongly dependent on the x value, which is interesti
ng for studying the relationship between microstructures and dielectri
c properties. Far infrared reflection spectra were also measured to st
udy the mixed phases formed in these ceramics in more detail.