Magnetoelectric Effect in Garnet Mn3Al2Ge3O12

Searching for novel magnetoelectric (ME) materials has been one of the major issues of multiferroics. In this work, we present a systematic research study on garnet Mn3Al2Ce3O12, including structural, magnetic, heat capacity, and ME characterizations. Below the Neel temperature TN similar to 6.8 K, Mn2+ spins form a long-range antiferromagnetic order, and a magnetic field H-driven electric polarization P is identified simultaneously. The relationship between P and H is nonlinear under low H and becomes linear under high H. Such transition is believed to originate from the H-induced variation of the magnetic structure. In addition, the P reaches 0.6 mu C/m(2) under mu H-0 = 9 T, corresponding to an ME coupling coefficient of alpha(ME) similar to 0.08 ps/m under high H. The small alpha(ME) is attributed to the weak spin-orbit coupling and weak magnetic interactions in Mn3Al2Ce3O12. Furthermore, we realize the stable control of P by periodically varying H, which is crucial for potential application. We provide a rare case that a garnet material shows a first-order ME effect.

Automated summary

Researchers conducted a systematic study on garnet Mn3Al2Ce3O12, revealing the formation of long-range antiferromagnetic order below the Néel temperature, as well as the observation of an electric polarization effect driven by a magnetic field. Stable control of polarization was achieved under high magnetic fields.