Large In-Plane Uniaxial Magnetic Anisotropy in the Ferromagnetic/Ferroelectric Heterostructures

Amorphous FeSiBC film with large magnetostriction and small magnetocrystalline anisotropy was deposited on the poled (110)-oriented Pb(Mg,Nb)O₃-PbTiO₃ crystal substrate to form ferromagnetic/ferroelectric (FM/FE) heterostructures. It is shown that large in-plane uniaxial magnetic anisotropy (IPUMA)(>250 Oe) can be induced upon applying in situ magnetic biasing field along the [001] direction during deposition. The IPUMA is tenfold of normally magnetic-field-induced anisotropy of FeSiBC/SiO₂/Si with the same biasing magnetic field, therefore dramatically pushing the FM resonance frequency from 1 to 4.2 GHz. Our investigation shows that the FE domain of the poled Pb(Mg,Nb)O₃-PbTiO₃ crystal can imprint into the FeSiBC layer and provide negative magnetic stress anisotropy upon applying biasing field along the [001] direction, but positive magnetic stress anisotropy upon applying biasing field along the [110] direction.