Magnetic ground state determination of the chalcomenite compound CuSeO3.2H2O

In the past two decades, the renaissance of multiferroics and the experimental discovery of skyrmions in MnSi has generated an explosion of interest in complex magnetic structures, especially for non-centrosymmetric cases. The chalcomenite mineral of formula CuSeO3.2H2O crystallizes in the non-centrosymmetric space group P212121. Susceptibility measurements reveal two anomalies: a broad peak at ~45 K, extending over a temperature range of 20K and likely due to the presence of short range interactions and a sharp peak at TN~26K (also seen in specific heat) signalling the onset of long range magnetic order. The crystal structure is built up from Cu(II) atom connected through the SeO3 bonds to other three copper atoms, giving rise a compact three dimensional network. From the presence of three exchange coupling paths, a complex magnetic ground state can be anticipated and is indeed seen in preliminary neutron data. The Cu...Cu connections through the SeO3 groups along the b-axis likely contribute to the short range order whilst. Due to the intrinsically low magnetic signal of the Cu(II) ions (S=1/2), we apply for 3 days on WISH with the goniometer to collect data at 1.5K and 50K to determine the ground state magnetic structure as well as looking for diffuse scattering just above TN.