Doping with different valence ions in Aurivillius compounds can induce lattice distortion and further affect the ferroelectric and magnetic properties of the materials. In this work, Ca_xBi_6–xFe_0.5Co_0.5Ti₄O₁₈ thin films were prepared to study the influence of the substitution of Ca²⁺ for Bi³⁺ on the microstructure and the dielectric, ferroelectric, leakage, and magnetic properties. The results show that the lattice distortion and the internal stress are both increased with increasing Ca²⁺ doping level. The dielectric and ferroelectric measurements suggest that the film with a low doping concentration (x = 0.2) exhibits better performance than the films with higher doping concentrations. Although lattice distortion and valence changes in the ions have been produced, which may have affected the distortion of the A/B-O octahedral crystal structure, tests of magnetic properties demonstrate that no regular changes are caused by the Ca²⁺ doping.

Graphical Abstract