Diameter and sequence effects on magnetoelectric effect in FeCo/Pb(Zr,Ti)O3/Ni trilayered long cylindrical composite structures

Here we studied the magnetoelectric (ME) effect of FeCo/Pb(Zr,Ti)O3/Ni and Ni/Pb(Zr,Ti)O3/FeCo trilayered long cylindrical composites made up of negative magnetostrictive Ni layers, positive magnetostrictive FeCo layers and piezoelectric Pb(Zr,Ti)O3 (PZT) cylinders. Magnetostrictive layers were directly deposited on the PZT by electroless deposition. The bias magnetic field and the frequency dependences of ME effect were studied in both the axial and the vertical modes. The mean diameter of the trilayered long cylindrical composites has a strong impact on the ME effect. Keeping the height fixed, the resonant frequency and the maximum ME voltage coefficient decrease with the mean diameter of the cylinder increasing, while the optimal bias magnetic field HDC approximately remains constant. Besides, the ME effect is also influenced by the sequence of Ni and FeCo layers. The FeCo/Pb(Zr,Ti)O3/Ni cylinder obtains larger ME voltage coefficients, superior to those of the Ni/Pb(Zr,Ti)O3/FeCo in both modes. This work is significant for optimizing ME performance of the cylindrical layered ME composites in practical application such as magnetic field sensors and energy harvesters.