Magnetoelectric Effect in $L 1_{0}$ -CoPd Thin Films

The effect of an applied electric field on the magnetic properties of L 1₀-ordered CoPd thin films is investigated by first-principle calculations. Both the magnetic moment and the magnetocrystalline anisotropy of the surface atoms are changed by the electric field, but the net effect depends on the surface termination. The magnetocrystalline anisotropy switches from in-plane to perpendicular in the presence of external electric field. Typical magnetic-moment changes are 0.1 μB per eV/Å. The main mechanism is the shift of the Fermi level, but the anisotropy change also reflects a crystal-field change due to incomplete screening.