Shear-mode self-biased magnetostrictive/piezoelectric laminate multiferroic heterostructures for magnetic field detecting and energy harvesting

• We propose a self-biased high-sensitivity magnetostrictive/piezoelectric magnetoelectric (ME) heterostructure operating in shear mode.
• A negative shear force as well as large internal anisotropic field is provided by SmFe2 plate due to its ferromagnetic and magnetostrictive properties.
• Relationship between the shear-mode driving force and ME coefficients is analyzed.
• This proposed laminate can be used in magnetic field detecting and energy harvesting without permanent magnets.

We report on a shear-mode off-antiresonance and antiresonance magnetoelectric (ME) responses in Tb0.3Dy0.7Fe1.92/Pb(Zr, Ti)O3/SmFe2 laminate multiferroic heterostructures for magnetic detecting and energy scavenging without bias field. A negative shear force as well as large internal anisotropic field is provided by SmFe2 plate due to its ferromagnetic and magnetostrictive properties, while the Terfenol-D plate provides a positive shear force to provoke a higher shear–stress transfer. Consequently, stronger ME coupling with a value of 2.24 V/Oe is obtained to be generated from the proposed architecture in the absence of the applied dc magnetic field. Experimental results exhibit an approximately linear sensitivity curve under off-antiresonance and antiresonance conditions, and the minimum stepped variations of input ac magnetic field as low as 2.43 × 10−8 T can be clearly distinguished under 111.5 kHz. In addition, a maximum power of 0.323 μW with a 2.6 MΩ load resistance in series connected to the ME laminate under the conditions of no bias can be achieved. These properties demonstrate that such a miniature multimode ME device is capable of weak magnetic field detecting and spatial magnetic energy scavenging by removing the requirement of dc bias field.