Mn-doping composition dependence of the structures, electrical and magnetic properties, and domain structure/switching of Aurivillius Bi5Ti3FeO15 films

Abstract Mn-doped Bi5Ti3FeO15 (BTFO) films were prepared by a chemical solution deposition route. The effect of a series of different Mn-doping concentrations from 0.05 to 0.4 on structures, electrical and magnetic properties, and domain structure/switching was systematically studied. Mn-doping into BTFO can avail the grain growth. Ferroelectric and dielectric properties are improved through Mn-doping, and the optimized Mn-doping content is 0.25 with remnant polarization of 17.2 μC/cm2 and permittivity of 371.2 at 10 kHz. Moreover, similar evolution of the permittivity and loss tangent with frequency to that of parent BTFO films appears in the BTFMO films when Mn-doping content is below 0.25, while obvious dispersion phenomena is demonstrated with further increasing Mn-doping content. A 180° domain structure and local ferroelectric switching are observed in all these Mn-doped BTFO thin films, and the piezo-displacement can reach 416 p.m. in 0.15 Mn-doped BTFO film. Finally, ferromagnetic properties appear in all these Mn-doped BTFO thin films. The coercive field shows weak temperature independence on Mn-doping contents, while the remnant magnetization is raised by Mn-doping.