Ionic-triggered magnetoelectric coupling for magnetic sensing applications

Abstract

The manipulation of electric properties by magnetic fields in magnetoelectric (ME) materials has driven significant research activity and industrial attention, as a result of their disruptive technological potential. Conventional ME nanocomposites exhibit low ME responses, involve electric poling, and AC magnetic excitation after fabrication. Such limitations hinder their full implementation in the scope of the digitalization of society (Internet of Things and Industry 4.0). In this work all those technological/scientific problems are jointly addressed through the nanoengineering of a new type of ME coupling, whose voltage response is ionic-triggered. The polymer-based nanocomposite with 20 weight percentage (wt.%) of [Bmim][Cl] ionic liquid and 30 wt.% of CoFe2O4 leads to the highest ME coupling coefficient reported in the literature (≈ 0.6 V.cm−1.Oe−1), value that is promising for applications, as demonstrated by its incorporation on a speed sensor.