Are optically active three-dimensional oxalate-based ferromagnets good candidates for the observation of x-ray magnetochiral dichroism? A neutron diffraction study

Neutron diffraction studies have been performed on [Ru(bpy)(2)(ppy)][MnCr(ox)] (bpy = 2,2'bipyridine; ppyH = 2-phenylpyridine; ox = oxalate), a 3D oxalate-based compound in one of its optically active forms. The diffraction pattern matches with the P2(1)3 space group found by x-ray diffraction. The magnetic structure has been studied in the magnetically ordered phase of the compound, e. g. below 5.5 K. The compound orders ferromagnetically. Owing to the most probable orientation of the spins, the magnetic space group is P2(1)2'(1)2'(1). The Shubnikov group is then 22'2'. Such a magnetic point group is compatible with the observation of x-ray magnetochiral dichroism, the occurrence of a ferromagnetic ordering being an important factor to enhanced the forecast effect.