Highly efficient solid state magnetoelectric gyrators

An enhancement in the power-conversion-efficiency (eta) of a magneto-electric (ME) gyrator has been found by the use of Mn-substituted nickel zinc ferrite. A trilayer gyrator of Mn-doped Ni0.8Zn0.2Fe2O3 and Pb(Zr, Ti) O-3 has eta = 85% at low power conditions (similar to 20 mW/in(3)) and eta >= 80% at high power conditions (similar to 5W/in(3)). It works close to fundamental electromechanical resonance in both direct and converse modes. The value of g is by far the highest reported so far, which is due to the high mechanical quality factor (Q(m)) of the magnetostrictive ferrite. Such highly efficient ME gyrators with a significant power density could become important elements in power electronics, potentially replacing electromagnetic and piezoelectric transformers.