  The magnetoelectric (ME) 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 well match 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.
