  Magnetic susceptibility, specific heat, dielectric, and electric polarization
of LiCuFe2(VO4)3 have been investigated. Two sequential antiferromagnetic
transitions at TN1 ~ 9.95 K and TN2 ~ 8.17 K are observed under zero magnetic
field. While a dielectric peak at TN1 is clearly identified, the measured
pyroelectric current also exhibits a sharp peak at TN1, implying the
magnetically relevant ferroelectricity. Interestingly, another pyroelectric
peak around TN2 with opposite signal is observed, resulting in the
disappearance of electric polarization below TN2. Besides, the electric
polarization is significantly suppressed in response to external magnetic
field, evidencing remarkable magnetoelectric effect. These results suggest the
essential relevance of the magnetic structure with the ferroelectricity in
LiCuFe2(VO4)3, deserving for further investigation of the underlying mechanism.

Materials Science;Strongly Correlated Electrons