The crystal structure and multiferroic properties of single-phase (Bi₀.₉La₀.₁)FeO₃–Ba(Fe₀.₅Nb₀.₅)O₃ ceramics were investigated. The rhombohedral-type structure of 1.0(Bi₀.₉La₀.₁)FeO₃) was transformed to a monoclinic-type structure for the 0.5(Bi₀.₉La₀.₁)FeO₃–0.5Ba(Fe₀.₅Nb₀.₅)O₃) composition. It shows the coexistence of ferroelectricity and magnetism at room temperature, represented by a high dielectric constant with ferroelectric hysteresis and clear magnetic hysteresis behavior. The authors propose that the solid solution of A and B site cations according to their ionic radii and valence state stabilized the spontaneous polarization and magnetization at room temperature.Keywords: valency, bismuth compounds, dielectric polarisation, permittivity, ferromagnetic materials, magnetic hysteresis, ferroelectricity, ferroelectric ceramics, multiferroics, barium compounds, crystal structure, lanthanum compounds, dielectric hysteresi
