In the digital era, magnetic storage technology is gradually becoming a hot spot in cutting-edge research. However, traditional magnetic storage devices have an inherent drawback: they rely on an electric current to generate a magnetic field to flip the direction of magnetization, a process that is accompanied by large energy losses, mainly in the form of heat. Therefore, how to further reduce the power consumption of magnetic storage without sacrificing performance has become the focus of researchers.
Multiferroic materials are seen as potential disruptors to next-generation storage technologies because they are both ferroelectric and ferromagnetic. Ideally, the magnetization of these materials should be able to be manipulated by an electric field rather than an electric current, effectively reducing energy consumption. However, for a long time, research has been limited by the general assumption that in order to effectively flip the direction of magnetization, the direction of the applied electric field must be consistent with the direction of magnetization reversal, which has constrained the development of multiferroic devices.
In response to this challenge, Assistant Professor Kei Shigemamatsu and Specially Appointed Associate Professor Hena Das of Tokyo Institute of Technology, together with graduate student Takuma Ito, Professor Masaki Higashi of East Institute of Technology, and Sumitomo Chemical Co., Ltd., have made a key breakthrough in the research of multiferroic materials. Their results were published in the journal Advanced Materials on April 28, 2025. The team first experimentally proved that in BiFe₀₉Co₀.In rare single-crystal thin-film polyferroic materials such as ₁O₃, magnetization flipping can be achieved even if the direction of the electric field is perpendicular to the direction of magnetization. The material exhibits ferroelectric and ferromagnetic coupling properties at room temperature, laying a realistic foundation for future applications.
Figure: Breakthrough in multiferroic materials: electric field-driven magnetization flip for low-power storage
The key to the success of this study is the growth of BiFe₀ in an unconventional crystal orientation₉Co₀.₁O₃ film. Through theoretical modeling and experimental proof, the researchers found that the electric field applied to the surface of the film in the parallel direction can trigger the magnetization flip in the vertical direction. This finding breaks with the traditional design thinking and shows that the polarization flip angle has a decisive influence on the direction of magnetization reversal.
Previously, multiferroic storage designs were generally based on the assumption that the electric field and the direction of magnetization must be collinear. In this study, we break through this limitation and propose a more flexible device design concept. "This increased design freedom allows for more flexible placement of polarized electrodes and magnetization sensors, which helps to make the most of BiFe₀.₉Co₀.Performance advantages of ₁O₃ materials. At the same time, achieving a higher level of integration is essential in memory technology, and this is what is possible with increased design freedom.
This highly integrated multiferroic memory is expected to not only reduce the overall power consumption of electronic devices, but also achieve both performance and storage capacity. "We believe that this achievement will greatly contribute to the development of next-generation magnetic memories and enable the creation of new storage solutions with high performance and high density," Shigemamatsu added.
Against the backdrop of rising global energy pressures and the increasing proliferation of electronic devices, any technological advances that improve energy efficiency and space efficiency are crucial. This research not only refreshes our understanding of the mechanisms by which multiferroic materials are manipulated, but also paves the way for more powerful and environmentally friendly digital technologies.
