Provided is an electroless iron bath capable of depositing a ferromagnetic FeB coating onto Pd/Sn-catalyzed substrates at room temperature without the need for an accompanying galvanic couple. The new electroless iron bath is comprised of Fe2+ as the metal source, citrate as the metal chelator, boric acid buffer as the pH controller, and borohydride as the reductant. Surface analysis following plating confirms the deposition of an amorphous FeB coating onto the surface of Pd/Sn-catalyzed cellulose microfibers.