Nanopillars with E-field accessible multi-state (N ≥ 4) magnetization having giant magnetization changes in self-assembled BiFeO3-CoFe2O4/Pb(Mg1/3Nb2/3)-38at%PbTiO3 heterostructures

We have deposited self-assembled BiFeO3-CoFe2O4 (BFO-CFO) thin films on (100)-oriented SrRuO3-buffered Pb(Mg1/3Nb2/3)0.62Ti0.38O3 (PMN-38PT) single crystal substrates. These heterostructures were used for the study of real-time changes in the magnetization with applied DC electric field (E DC ). With increasing E DC , a giant magnetization change was observed along the out-of-plane (easy) axis. The induced magnetization changes of the CFO nanopillars in the BFO/CFO layer were about ΔM/M rDC  = 93% at E DC  = −3 kv/cm. A giant converse magnetoelectric (CME) coefficient of 1.3 × 10−7 s/m was estimated from the data. By changing E DC , we found multiple(N ≥ 4) unique possible values of a stable magnetization with memory on the removal of the field.