Observation of magnetoelectric effects in a S=12 frustrated spin chain magnet SrCuTe2O6

The magnetoelectric effects are investigated in a cubic compound SrCuTe2O6, in which uniform Cu2+ (S = 1/2) spin chains with considerable spin frustration exhibit a concomitant antiferromagnetic transition and dielectric constant peak at TN ≈ 5.5 K. Pyroelectric Jp(T) and magnetoelectric current JME(H) measurements in the presence of a bias electric field are used to reveal that SrCuTe2O6 shows clear variations of Jp(T) across TN at constant magnetic fields. Furthermore, isothermal measurements of JME(H) also develop clear peaks at finite magnetic fields, of which traces are consistent with the spin-flop transitions observed in the magnetization studies. As a result, the anomalies observed in Jp(T) and JME(H) curves match well with the field-temperature phase diagram constructed from magnetization and dielectric constant measurements, demonstrating that SrCuTe2O6 is a new magnetoelectric compound with S = 1/2 spin chains.