Electric field control of nonvolatile four-state magnetization at room temperature

Abstract: We find the realization of large converse magnetoelectric (ME) effects at room temperature in a multiferroic hexaferrite Ba${0.52}$Sr${2.48}$Co${2}$Fe${24}$O${41}$ single crystal, in which rapid change of electric polarization in low magnetic fields (about 5 mT) is coined to a large ME susceptibility of 3200 ps/m. The modulation of magnetization then reaches up to 0.62 $\mu$${B}$/f.u. in an electric field of 1.14 MV/m. We find further that four ME states induced by different ME poling exhibit unique, nonvolatile magnetization versus electric field curves, which can be approximately described by an effective free energy with a distinct set of ME coefficients.