Multiferroic behavior in the quasi-one-dimensional frustrated spin-1/2 system PbCuSO4(OH)2 with CuO2 ribbon chains

Magnetic and dielectric properties have been studied for single- and polycrystalline samples of PbCuSO4(OH)2 with quasi-one-dimensional spin-1/2 chains composed of edge-sharing CuO4 square planes called CuO2 ribbon chains. The dielectric constant and polarization measurements indicate that a ferroelectric transition takes place simultaneously with magnetic transition at the Neel temperature TN - 2.8 K. From the magnetization curves of the single crystalline sample at 2 K, spin flop transition is found at Hc - 2.5 T for the H parallel CuO2 plane. On the basis of detailed magnetization and dielectric constant measurements, the possible magnetic structure and the origin of the ferroelectricity of the compound are discussed. (author)