A research team from Osaka University, The University of Tokyo, and Tokyo Institute of Technology revealed the microscopic origin of the large magnetoelectric effect in interfacial multiferroics composed of the ferromagnetic Co2FeSi Heusler alloy and the piezoelectric material. They observed element-specific changes in the orbital magnetic moments in the interfacial multiferroic material using an X-ray Magnetic Circular Dichroism (XMCD) measurement under the application of an electric field, and they showed the change contributes to the large magnetoelectric effect.
The findings provide guidelines for designing materials with a large magnetoelectric effect, and it will be useful in developing new information writing technology that consumes less power in spintronic memory devices.
The research results will be shown in an article, “Strain-induced specific orbital control in a Heusler alloy-based interfacial multiferroics” published in NPG Asia Materials.
Controlling the direction of magnetization using low electric field is necessary for developing efficient spintronic devices. In spintronics, properties of an electron’s spin or magnetic moment are used to store information. The electron spins can be manipulated by straining orbital magnetic moments to create a high-performance magnetoelectric effect.
Japanese researchers, including Jun Okabayashi from the University of Tokyo, revealed a strain-induced orbital control mechanism in interfacial multiferroics. In multiferroic material, the magnetic property can be controlled using an electric field — potentially leading to efficient spintronic devices. The interfacial multiferroics that Okabayashi and his colleagues studied consist of a junction between a ferromagnetic material and a piezoelectric material. The direction of magnetization in the material could be controlled by applying voltage.
The team showed the microscopic origin of the large magnetoelectric effect in the material. The strain generated from the piezoelectric material could change the orbital magnetic moment of the ferromagnetic material. They revealed element-specific orbital control in the interfacial multiferroic material using reversible strain and provided guidelines for designing materials with a large magnetoelectric effect. The findings will be useful in developing new information writing technology that consumes less power.
