Polycrystalline BiFe0.9Mn0.1O3 thin films have been prepared on Pt/Ti/SiO2/Si wafers by a sol-gel process. The film exhibits typical resistive switching (RS) effect. Moreover, accompanied with the RS process, remarkable magnetization switching (MS) behaviors happen, i.e., at low resistance state the film shows high saturation magnetization, while showing low saturation magnetization at high resistance state. We revealed that such a MS effect mainly originates from the conversion of Fe ion valence state between Fe2+ and Fe3+ during the RS process, which was confirmed by the x-ray photoelectron spectroscopy measurements. The further first-principle calculations showed that the doping of Mn into the BiFeO3 could induce an impurity energy level which makes it facile to achieve the conversion of Fe ion valence state. Based on the conductive filament model, a possible mechanism of tuning the MS effect by RS process is proposed, which is closely related to the conversion of Fe ion valence state along with the forming and rupture of conduction filaments. This work provides us a promising avenue to design switchable multistate devices with both electric and magnetic functionalities.

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The magnetic dynamics of a thin Co2FeAl film epitaxially grown on GaAs substrate was investigated using the time- resolved magneto-optical Kerr measurement under an out-of-plane external field. The intrinsic magnetic damping constant, which should do not vary with the external magnetic field, exhibits an abnormal huge increase when the precession frequency is tuned to be resonant with that of the coherent longitudinal acoustic phonon in the Co2FeAl/GaAs heterostructure. The experimental finding is suggested to result from the strong coherent energy transfer from spins to acoustic phonons via magnetoelastic effect under a resonant coupling condition, which leads to a huge energy dissipation of spins and a greatly enhanced magnetic damping in Co2FeAl. Our experimental findings provide an experimental evidence of spin pumping-like effect driven by propagating acoustic phonons via magnetoelastic effect, suggesting an alternative approach to the possible long-range spin manipulation via coherent acoustic waves.