Magnetoelectric coupling characteristics of multi-phase laminate heterostructures based on FeCuNbSiB nanocrystalline soft magnetic alloy

Over the last decade, multiferroic laminate heterostructures, consisting of the piezoelectric layer (such as PZT) and the magnetostrictive layer (such as Terfenol-D), have attracted considerable attention due to their high Curie or Neel temperature and large magnetoelectric (ME) effect at room temperature. The ME laminate materials have demonstrated potential in many applications such as transducers, actuators, magnetic field sensors, energy harvesters, and other devices [1] . ME effect in the multiferroic laminated heterostructures is essentially attributed to the elastic coupling between the piezoelectric and magnetostrictive layers [2] . The effective piezomagnetic coefficient and effective mechanical quality factor play a key role in the performance of the ME materials. However, owing to the small values of the mechanical quality factor and relative permeability, the ME voltage coefficient of the traditional Terfenol-D/PZT (MP) composites is difficult to increase [3, 4] . The nanocrystalline FeCuNbSiB soft magnetic alloy would be a good solution, according to the large interface stress-strain coupling effects. In this paper, a series of FeCuNbSiB/Terfenol-D/PZT (F/M/P) multi-phase laminate heterostructures are presented (Fig. 1), whose ME coupling characteristics have been investigated. Compared to traditional MPM, the ME coupling characteristics of the proposed FMPMF heterostructures were significantly improved. The resonant and low-frequency ME voltage coefficient of the proposed F/M/P heterostructures could be tuned by controlling the layer numbers N. When N is 7 (FMPMPMF), the maximum value of resonant ME voltage coefficient achieves 8.69 V/Oe, which is about 3.65 times higher than that for FMP, 1.81 times higher than that for FMPMF (Fig. 2(a)). Meanwhile, the maximum value of low-frequency ME voltage coefficient for FMPMPMF heterostructures achieves 69.6 mV/Oe at H b =378 Oe (Fig. 2(b)). Remarkably, it indicates that the F/M/P heterostructures have great potential as far as its application in highly sensitive dc magnetic field sensing and vibration energy harvesting.