Aurivillius phases of PbBi4Ti4O15 doped with Mn3+ synthesized by molten salt technique: Structure, dielectric, and magnetic properties

Doping of manganese (Mn3+/Mn4+) into the Aurivillius phase Pb1−xBi4+xTi4−xMnxO15 was carried out using the molten salt technique for various Mn concentrations (x=0, 0.2, 0.4, 0.6, 0.8, and 1). Single phase samples could be obtained in the composition range with x up to 0.6 as confirmed by X-ray and neutron diffraction analysis. Dielectric measurements show a peak at 801, 803, 813 and 850 K for samples with x=0, 0.2, 0.4, and 0.6, respectively, related to the ferroelectric transition temperature (Tc). The main contribution of the in-plane polarization for x≤0.2 which was calculated from the atomic positions obtained by the structure analysis is the dipole moment in the Ti(1)O6 layer; however, for x≥0.4 the polarization originates from the dipole moment in the Ti(2)O6 layer. Mn doping in the Pb1−xBi4+xTi4−xMnxO15 does not show any long range magnetic ordering.

The dipole moment of TiO6 dependence of x in Pb1−xBi4+xTi4−xMnxO15 (0≤x≤0.6): (a) along a-axis and (b) on the ab plane. This figure indicated that polarization in the ab-plane contribute to the total polarization.Figure optionsDownload as PowerPoint slideHighlights
► We have prepared Pb1−xBi4+xTi4−xMnxO15, 0≤x≤1 by the molten-salt method.
► The oxides adopted A21am space group.
► Dipole moments of the inner Ti(1)O6 are the main polarization contributor for x≤0.2.
► Dipole moments of the outer Ti(2)O6 are the main polarization contributor for x>0.2.
► Ferromagnetic interactions show the contribution of mixed valence of Mn3+/Mn4+.