Dynamic manipulation of piezotronic behaviors of composite multiferroic semiconductors through time-dependent magnetic field

摘要

A dynamic non-contact approach to tuning the semiconducting (SM) properties of multiferroic composite semiconductor (MCS) fibers by applying a time-dependent magnetic field is proposed and theoretically demonstrated in this paper. The considered fiber is symmetric with respect to its geometrical middle plane and made from two outer piezomagnetic (PM) layers, two piezoelectric (PE) layers, and a SM core. Through the interface strain or deformation transfer, the MCS fiber exhibits not only the conventional magnetoelectric (ME) coupling effect but also the comprehensive magneto-electro-semiconductive (MES) coupling effect. Based on a one-dimensional model for the MCS fibers, we present the analytical solutions for the physical fields of the MCS fiber with a pure longitudinal deformation under a time-dependent magnetic field. The electrons redistribute themselves in the MCS fiber under the driving of the induced piezoelectric field due to the MES coupling effect. Near the natural frequencies, the magnetic field has a remarkable tuning effect. The ME and MES coefficients achieve their local peak values at the natural frequencies. There is an optimal range for the volume fraction of the PM or PE layer for the MES coupling effects. We can manipulate the electrons to assemble in multiple local regions in the MCS fiber by setting the exciting frequency to a specific higher natural frequency. This provides a new way to explore multi-tunnel electronic devices through the dynamic contactless magnetic control approach.