Superior room-temperature magnetic field-dependent magnetoelectric effect in BiFeO₃-based multiferroic

Multiferroics that exhibit simultaneous electric and magnetic orders have attracted a great deal of interests both in fundamental science and practical applications. In general, high-performance single-phase multiferroics are extremely rare, owing to the incompatibility between ferroelectricity and magnetism. The most interesting property that makes multiferroics useful in device applications is the direct and significant magnetoelectric coupling at room temperature, resulting in a hysteretic magnetoelectric response. However, it still remains a great challenge to realize such a cross-coupling hysteresis loop between the ferroelectric and magnetic orders, i.e. an effective magnetic command of polarization, or an electric-field command of magnetization in a single-phase bulk material. Here we report the multiferroic behavior of chemically modified bismuth ferrite, Bi_0.88Dy_0.12Fe_0.97Ti_0.03O_3+δ, which exhibits simultaneous (weak) ferromagnetism and ferroelectricity. More interestingly, this solid solution shows an evident magnetoelectric effect at a low magnetic field by demonstrating a hysteretic loop that characterizes the electric voltage signal as a function of bias magnetic field. Moreover, the room-temperature magnetoelectric effect with the saturated magnetoelectric coefficient up to ±0.23 mV/cm•Oe at ±250 Oe is obtained. The observed properties are attributed to the combination of linear magnetoelectric effect and domain wall motion. This result points to potential new applications of single-phase multiferroic materials in spintronic devices in which electric dipoles can be effectively tuned by a magnetic field.