The influence of nanometric phase separation on the dielectric and magnetic properties of (1 − x)BaTiO3–xLaYbO3 (0 ≤ x ≤ 0.60) ceramics

X-Ray diffraction analysis shows the co-solubility of La3+ and Yb3+ into BaTiO3 according to the formulae LaxBa1−xTi1−xYbxO3 (LBTYb) to be as high as x = 0.45. Raman spectroscopy analysis suggests the occurrence of continuous ion clustering with increasing x, which culminates with nanometric phase separation at x ≥ 0.35, as revealed by dark-field transmission electron microscopy. The room temperature relative permittivity, εRT, of LBTYb ceramics decreases from 1600 for x = 0 to 62 for x = 0.45. The Curie temperature, Tc, of LBTYb ceramics decreases at a average rate of 23 K/at% La/Yb for x ≤ 0.20. Relaxor-type behaviour is observed for 0.10 ≤ x ≤ 0.35. A nearly linear dielectric response is observed for 0.40 ≤ x ≤ 0.45, but below 25 K, εr decreases sharply, whereas the magnetic susceptibility increases. The microwave dielectric properties of x = 0.40 ceramics are εRT 65 and tan δ 0.01 at 5 GHz. The high dielectric loss may be primarily associated with anharmonic phonon interactions resulting from the phase separation.