Influence of the magnetic anisotropy in the X-ray magnetochiral dichroism

This proposal aims at studying the effect of single-ion magnetic anisotropy on X-ray magnetochiral dichroism (XMχD). The effect is closely related to the linear magneto-electric effect and described by orbital and spin toroidal current (anapole moments) in the absorbing atom that has no inversion symmetry. XMχD was successfully detected and studied not only at the K-edges of transition metal complexes[1] but also at the L3-edge of Holmium in chiral paramagnetic crystals of Na5[Ho(ODA)3](BF4)2·6H2O.[2] Its isostructural Dysprosium analogue, hereafter referred to as Dy(ODA)3, exhibits a very unusual magnetic property, namely a switching of the magnetic anisotropy from easy-axis to easy-plane, induced by temperature or applied magnetic field. This is why this chiral paramagnetic crystal was selected to investigate the effect of magnetic anisotropy on XMχD response at the L2,3-edges of Dysprosium.