Switching time of electrical tuning of permeability in strain-mediated multiferroic heterostructures

Abstract

The switching time of the electrically tunable permeability of the NiFeTa/[Pb(Mg1/3Nb2/3)O3]0.68-[PbTiO3]0.32 multiferroic material was characterized by using a Vector Network Analyzer and a pulse generator. The measured switching time for the permeability to be electrically tuned from the initial value to the final value upon the change of the applied electrical field is 0.15 s, which is independent of the magnitude of the electrical field and the measured frequency. The result is verified by the measurement of the time response permeability under a series of pulses with different pulse widths. It was found that for the cases of the pulse width smaller than the switching time, the rise time of the permeability response pulse is the same as the pulse width and the pulse height of the response permeability is linearly dependent on the pulse width. It is suggested that the temporal relaxation process of the interface arising from the strain transfer delay time between the film and the substrate plays a dominant role in the contribution of the total switching time of the material.