Electric-Field Control of Low Damping Constant in Epitaxial Co₂FeSi/LiNbO₃ Multiferroic Heterostructures

To develop electric-field control of magnetization dynamics in a magnetic material for magnonic devices with low-energy power consumption operation, an epitaxial half-metallic Co₂FeSi/LiNbO₃ multiferroic heterostructure is experimentally demonstrated. The epitaxial Co₂FeSi/LiNbO₃ multiferroic heterostructure shows a low damping constant (α) of ∼0.006 and the value of α is decreased to ∼0.004 by applying an electric field. This means that the magnetization dynamics in an epitaxial half-metallic Co₂FeSi layer can be controlled via the piezoelectric strain of LiNbO₃ through the magnetoelastic coupling. This study leads to a way toward the realization of magnonic devices with low-energy power consumption operation.