By definition, nanocrystalline materials consist of single or multiphase polycrystals with grain diameters less than 50 nm. Materials of this type can be synthesized by many techniques, including: compacted nanoparticles, thin film deposition, and devitrified metallic glasses. This talk will serve to review the recent activity in the devitrification of metallic glass ribbons, with a focus on processing-structure-property relationships as outlined in the recent review chapter . HitPerm alloys will be given a special focus in this presentation to honor Prof. M. E. McHenry and his contributions to the science and engineering of these materials.
 Matthew A. Willard and Maria Daniil, Nanocrystalline Soft Magnetic Alloys Two Decades of Progress. In K.H.J. Buschow, editor: Handbook of Magnetic Materials, Vol. 21, Amsterdam: The Netherlands, 2013, pp. 173-342.