Strain-mediated electric-field control of exchange bias in a Co90Fe10/BiFeO3/SrRuO3/PMN-PT heterostructure

The electric-field (E-field) controlled exchange bias (EB) in a Co90Fe10/BiFeO3(BFO)/SrRuO3/PMN-PT heterostructure has been investigated under different tensile strain states. The in-plane tensile strain of the BFO film is changed from +0.52% to +0.43% as a result of external E-field applied to the PMN-PT substrate. An obvious change of EB by the control of non-volatile strain has been observed. A magnetization reversal driven by E-field has been observed in the absence of magnetic field. Our results indicate that a reversible non-volatile E-field control of a ferromagnetic layer through strain modulated multiferroic BFO could be achieved at room temperature.