Influence of rare earth ions on ba0-ti02-rare earth oxide ceramics for microwave applications

The dielectric ceramic materials, 0.143BaO-0.714TiO₂-0.143 rare earth oxides (REO_x), have unique dielectric properties at microwave frequencies, which depend on the rare earth element (RE=Pr, Nd, Sm). In order to study the effect of the rare earth ions on dielectric properties, infrared reflection spectra of these ceramics were measured from 50 to 4000 cm^-1 at room temperature. These data were analyzed according to the model proposed by Gervais and Piriou. Also, the fourth-order dielectric constants of these materials were estimated for the purpose of investigating the relationship between the dielectric loss and the anharmonic terms in the potential energy.