Microwave dielectric properties of Bi-substituted La(Mg1/2Ti1/2)O3

The system La(Mg1/2Ti1/2)O3-Bi(Mg1/2Ti1/2)O3 (LMT-BMT) was investigated in respect to formation of perovskite solid solutions based on lanthanum magnesium titanate. Single-phase perovskite (1 − x)LMT-xBMT ceramics (0 ≤ x ≤ 0.3) were prepared and their crystal structure and dielectric properties were studied. It has been found that within the solubility range the crystal structure of Bi-substituted LMT remains monoclinic, P21/n. Unit cell volume was evaluated to be almost independent on x, varying within the experimental error. Relative permittivity of the ceramics increases by almost a factor of 3 in the range 0 ≤ x ≤ 0.3 and its value is 40-45 at the compositional region where temperature coefficient of the resonant frequency passes a zero-value. Compositional and temperature variations of the dielectric parameters for LMT-BMT estimated at different frequency ranges are considered in comparison with those observed in other Bi-substituted ceramics based on LMT.