Polarized Neutron Reflectivity study of in-plane spin vortices formed in 2D rare-earth magnetic systems

Spin vortices are most appealing characteristics of two dimensional 2D easy-plane spin systems which are receiving recent attention for their fundamental properties and possible technological applications involving nanostructured magnetic materials. Spin vortices are in-plane circular spinarrangements which may have core spins directing out-of plane to reduce exchange energy. A spin vortex exists together with its counterpart, known as anti-vortex, as a pair below a characteristic temperature, known as the Berezinskii-Kosterlitz-Thouless (BKT) transition. . Neutron scattering can only determine Bohr Magnetron per magnetic ion, this gives an unique measure of the BKT temperature of a 2D magnetic structure. We propose to measure this temperature as a function of orbital moment using Ho, Er and Gd based LB films that form 2D magnetic structures.