TY  - JOUR
AU  - Zhao, L.
AU  - Guo, H.
AU  - Schmidt, W.
AU  - Nemkovskiy, Kirill
AU  - Mostovoy, M.
AU  - Komarek, A. C.
TI  - Magnetically induced ferroelectricity in Bi$_2$CuO$_4$
JO  - Physical review / B
VL  - 96
IS  - 5
SN  - 2469-9950
CY  - Woodbury, NY
PB  - Inst.
M1  - FZJ-2017-07202
SP  - 054424
PY  - 2017
AB  - The tetragonal copper oxide Bi2CuO4 has an unusual crystal structure with a three-dimensional network of well separated CuO4 plaquettes. The spin structure of Bi2CuO4 in the magnetically ordered state below TN∼43 K remains controversial. Here we present the results of detailed studies of specific heat, magnetic, and dielectric properties of Bi2CuO4 single crystals grown by the floating zone technique, combined with the polarized neutron scattering and high-resolution x-ray measurements. Down to 3.5 K our polarized neutron scattering measurements reveal ordered magnetic Cu moments which are aligned within the ab plane. Below the onset of the long range antiferromagnetic ordering we observe an electric polarization induced by an applied magnetic field, which indicates inversion symmetry breaking by the ordered state of Cu spins. For the magnetic field applied perpendicular to the tetragonal axis, the spin-induced ferroelectricity is explained in terms of the linear magnetoelectric effect that occurs in a metastable magnetic state. A relatively small electric polarization induced by the field parallel to the tetragonal axis may indicate a more complex magnetic ordering in Bi2CuO4.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000407924600002
DO  - DOI:10.1103/PhysRevB.96.054424
UR  - https://juser.fz-juelich.de/record/838625
ER  -