Electric field tuning of ferromagnetic resonance field and linewidth in epitaxial LiFe5O8/PMN-PT (011) heterostructure

Here a typical ME heterostructure is prepared by growing epitaxial LiFe5O8 (LFO) thin films on Pb(Mg1/3Nb2/3) O3-PbTiO3 (PMN-PT) (011) substrates by pulse laser deposition (PLD). Ferromagnetic resonance (FMR) test results at in situ voltage show that the tunability of FMR field (Hr) and linewidth (Delta H) have strong angular dependences with external magnetic field. It is inferred that the change of the orientation of equilibrium magnetization contributes to the abnormal enhancement of ME coupling at certain angles. The theoretical fitting reveals that the Gilbert damping (Delta HGilb), two-magnon scattering (Delta HTMS) and inhomogeneous broadening (Delta Hinhom) play the different roles for the increase of linewidth of LFO film at various magnetic field directions. Additionally, the ME coupling in LFO/PMN-PT (011) heterostructure shows well temperature stability at range of 100-300 K. Those discoveries enrich the understanding of the ME phenomenon and provide guidance to the development of novel multiferroic materials and devices.