Magnetodielectric effect in lead-free multiferroic CoFe2O4/K0.5Na0.5NbO3 bilayers

In this letter we presented the investigations of magnetodielectric (MD) effect in lead-free multiferroic CoFe2O4/Na0.5K0.5NbO3 (CFO/KNN) bilayers with constant volumes. The CFO/KNN bilayers were synthesized on conductive Nb-doped SrTiO3 (001) single-crystal substrates by radio frequency magnetron sputtering. Noticeable MD effect was observed in these CFO/KNN bilayers. The MD coefficient depends on the volume fraction of CFO layer. A maximum MD coefficient of about 7% at 12 kOe at 2 kHz was observed in 0.6CFO/0.4 KNN bilayer. The MD effect is attributed to strain-mediated magnetoelectric effect and magnetoresistance effect combined with the Maxwell–Wagner effect. The MD effect may have possible applications in magnetic field sensing devices.

► Lead-free CoFe2O4/Na0.5K0.5NbO3 bilayers were deposited by magnetron sputtering.
► Noticeable magnetidielectric effect was observed.
► Magnetodielectric effect has potential applications in magnetic field sensing devices.