Importance of composite parameters in enhanced power conversion efficiency of Terfenol-D/PZT magnetoelectric gyrators

A gyrator that is capable of current-to-voltage conversion can be realized with a magnetoelectric (ME) composite of ferromagnetic and ferroelectric phases placed in a coil. Here, we report the dependence of the power conversion efficiency (PE) on the relative thickness of the two ferroic phases in a gyrator of Terfenol-D and PZT. Both experimental and theoretical results on PE as a function of composite parameters, such as thickness ratio of the ferroic layers (n), magnetic field bias (H-Bias) and several gyrator parameters, such as the resistance load (R-L), were discussed. By decreasing the thickness ratio of Terfenol-D to composite (n = 0.28) in coil-ME gyrators, a high power efficiency of 73.9% was found at a fundamental resonance frequency of 72.5 kHz under a H-Bias of 1000 Oe and RL = 2.6 k Omega in experiments. At the same time, the non-linear mechanical loss was reduced by decreasing the value of n which resulted in a flat response over a wide HBias range. This improved power efficiency promises ME gyrators for power transfer devices. Published by AIP Publishing.