The magnetoelectric effect in a cubic ferrimagnetic spinel LiFe ₅ O ₈ with high coupling temperature

We report an effective magnetoelectric (ME) coupling phenomenon in cubic ferrimagnetic spinel LiFe ₅ O ₈ , with the command of its polarization by an applied magnetic field. A hysteretic response between magnetic field and electric polarization was observed. It is found that LiFe ₅ O ₈ exhibits ME coupling that becomes significant at 250 K and increases with decreasing temperature. In contrast to many other spinel oxides that were reported to exhibit a ME effect at very low temperatures (typically below 30 K), the bulk LiFe ₅ O ₈ demonstrates a ME coefficient of 2 mV Oe ⁻¹ cm ⁻¹ at 120 K. This material exhibits the highest ME coupling temperature among the magnetoelectric spinel and related materials reported so far. This ME effect is attributed to the ordered arrangement of magnetic ions (Fe ³⁺ ) which are located in a noncentrosymmetric coordination environment. Our result provides a new avenue to search for single-phase magnetoelectric materials with high coupling temperatures that could be used in potential technological applications.