The effect of Mn doping contents on the structural, dielectric and magnetic properties of multiferroic Bi5Ti3FeO15 Aurivillius ceramics

Aurivillius Bi5Ti3FeO15 (BTFO) multiferroic ceramics with different Mn doping contents were synthesized through the conventional solid state reaction. The effect of Mn doping on the structural, magnetic and dielectric behaviors of BTFO ceramics is investigated in detail. All these Mn-doped BTFO ceramics are determined to be layered Aurivillius structure by X-ray diffraction. No microstructure variation of plate-like grains is obviously confirmed due to Mn doping through field emission scanning electron microscopy. Similar evolution of ε and tan δ with frequency is found both in BTFO and 10% Mn-doped BTFO ceramics. However, obvious dielectric dispersion phenomena are presented as the Mn-doping content is beyond 0.1, and this dispersion behavior becomes strong with increasing Mn-doping content, clearly indicated by the appearance of dielectric loss relaxation peaks. Finally, the same magnetic orders of 10% Mn-doped BTFO ceramics as those of the BTFO one are unambiguously found while weak ferromagnetism is observed in BTFO ceramics with Mn-doping content beyond 0.2.