A piezoelectric Mn doped PMN-PT/Metglas magnetoelectric gyrator: Enhanced power efficiency at reduced size

Magnetoelectric (ME) composites with ferromagnetic and ferroelectric phases show a strong coupling between the magnetic and electric subsystems that occurs through mechanical strain. Such composites are suitable for applications such as transducers that convert magnetic and electric energies. An important issue that needs to be considered is the magnetic-to-electric energy conversion efficiency. For applications under high power, energy transduction requires a high mechanical stability that minimizes the loss during conversion. Here, the high drive mechanical stability of Mn-doped Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) crystals has been enhanced by external magnetic field when bonded to Fe-rich Metglas foils. External field modulation stabilizes the mechanical quality factor under high power drive. A magnetoelectric gyrator was then made that had an excellent power conversion efficiency of $\eta ={92}$ %, but which also had a dramatically decreased size as compared to similar gyrators made of “hard” Pb(Zr,Ti)O3 (PZT) ceramics. The findings provided an approach to optimizing the size-weight-power space of ME gyrators for power converters.