MnO_2-doping induced enhanced multiferroicity in Bi_(0.83)Sm_(0.17)Fe_(0.95)Sc_(0.05)O_3 ceramics

摘要

Multiferroic material BiFeO_3 (BFO) that possesses spin and dipole orders simultaneously at ambient temperature shows great potential in multi-state memory and spintronic devices. Nevertheless, the presence of low polarization and weak magnetism in ceramics heavily restricts their applications. Here, the charge compensation method was utilized to reduce leakage current and enhance dielectric breakdown strength (E_b) by introducing MnO_2 in Bi_(0.83)Sm_(0.17)Fe_(0.95)Sc_(0.05)O_3 ceramics. It was revealed that all the ceramics have the coexistence of polar R3c and nonpolar Pnma phases. With increasing MnO_2, E_b is significantly improved, leading to the enhanced ferroelectric polarization. A high remanent polarization of ≈51.54 μC/cm~2 was achieved in the composition with 0.9 wt. % MnO_2 doping, which is the maximum in the reported BFO-based ceramics. Meanwhile, a rather high remanent magnetization of ≈0.31 emu/g was obtained in the same compound. Therefore, this work reveals an interesting route to tailor BFO-based ceramics toward enhanced multiferroicity.