Fabrication of an electrode with a surface coated with a magnetic composite with a number of boundary regions with magnetic gradients having paths to the surface of the electrode comprises: (a) mixing a mixture of 1 wt.% inert polymer-coated magnetic microbeads containing (10 wt.% magnetisable material and having diameters of (0.11 (m in a 1st solvent with a mixture comprising (2 wt.% of an ion exchange polymer in a 2nd solvent to give a mixed suspension; (b) applying the suspension to the surface of the electrode which is arranged in a magnetic field of (0.05 Tesla which has a component oriented approximately along the normal of the electrode surface; and (c) evaporating the solvents to leave the magnetic composite layer. Also claimed is the fabrication of a electrode surface coated with a composite having a number of boundary regions with magnetic gradients having paths to the surface of the electrode when an external magnetic field is applied to the electrode by: (a) mixing a mixture of (5 wt.% inert polymer-coated microbeads, containing 10-90% magnetisable non-permanent magnetic material, having diameters of (0.5 (m in a 1st solvent with ( 5% ion exchange polymers in a 2nd solvent to give a mixed suspension; (b) applying to the electrode surface; and (c) evaporating the solvents to give a coated electrode with a number of magnetic gradients with paths to surface of electrode when an external magnet is applied. Further claimed is the coating of a surface with a magnetic composite material by applying a composition containing inert polymer-coated magnetic microbeads, an ion exchange polymer and solvent, arranging in a magnetic filed and evaporating solvent.    USE -   Used for separators, fuel cells, electrochemical cells, and electrodes for channelling flux of or for effecting electrolysis of magnetic species.    ADVANTAGE -   The electrode has improved flux of paramagnetic species and improved flux of oxygen to the cathode in a fuel cell. It can separate paramagnetic, diamagnetic and non-magnetic chemical species from a mixture. It can separate species according to chemical, viscosity and magnetic properties. It can work with internal or external magnetic fields or both.