Most materials we use in everyday life expand slightly when heated and return to their original size when cooled. In addition to such thermal properties, materials can also have electrical properties or magnetic properties, and traditionally we have used these characteristics separately. However, some materials allow multiple properties to coexist within a single substance.

Research on such materials is expected to contribute to the development of next-generation memory devices that can store and retain information while consuming far less energy.

How multiferroics could transform memory A representative example is a class of materials known as multiferroics, which combine the properties of a capacitor (the ability to store electric charge) and a magnet. Among them, bismuth ferrite (BiFeO₃) is one of the most intensively studied materials in the field. When an external voltage is applied, the direction of its stored electric polarization can be switched, and this change can also influence its magnetic properties.