An easy way to measure accurately the direct magnetoelectric voltage coefficient of thin film devices

摘要

Tb_xDy_(1-x)Fe_2/Pt/Pb(Zr_x, Ti_(1-x))O_3 thin films were grown on Pt/TiO_2/SiO_2/Si substrate by multi-target sputtering. The magnetoelectric voltage coefficient α_(ME)~H was determined at room temperature using a lock-in amplifier. By adding, in series in the circuit, a capacitor of the same value as that of the device under test, we were able to demonstrate that the magnetoelectric device behaves as a voltage source. Furthermore, a simple way to subtract the stray voltage arising from the flow of eddy currents in the measurement set-up, is proposed. This allows the easy and accurate determination of the true magnetoelectric voltage coefficient. A large α_(ME)~H of 8.3 V/cm. Oe was thus obtained for a Terfenol-D/Pt/PZT thin film device, without DC magnetic field nor mechanical resonance.