“…Generally, high ε r and positive τ f were obtained for the former, while relatively low ε r and negative τ f were observed for the latter. The effect of microstructure on properties of RETiNbO 6 (RE = La, Sm, and Y) ceramics was presented by Lei et al [159]. The dielectric constant of RETiNbO 6 system (RE = Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Y, and Yb) and RETiTaO 6 (RE = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Y, Er, Yb, Al, and In) increases with the RE ionic radius [157,158].…”