Magnetoelectric effect of Fe₇₀Pd₃₀ ferromagnetic shape memory alloy film: Lead zirconate titanate trilayer composites at low and high magnetic field frequencies

Magnetoelectric (ME) coupling in multiferroic composites of Fe ₇₀Pd₃₀/lead zirconate titanate (PZT)/Fe ₇₀Pd₃₀ trilayers was investigated. An Fe ₇₀Pd₃₀ ribbon and Fe₇₀Pd₃₀ films were prepared by rapid solidification and sputtering techniques, respectively. The saturated value of magnetostriction of the ribbon 30 ×m in thickness was 95 ppm at a steady magnetic field of 200 Oe. Those of the films were 22 to 67 ppm depending on the film thickness. The output ME voltage V_ME of the trilayer composites, which was measured at a driving ac magnetic field H_ac at 1 Hz, increased with increasing magnetostriction. The V _ME of the ribbon/PZT/ribbon composite exhibited a very large peak at a resonant frequency of 64 kHz and responded to an H_ac of 0.0025 Oe. However, for the film/PZT/film composite, V_ME linearly increased with increasing H_ac in a wide frequency range of 1 to 10₄ Hz.