Developing Biotemplated Data Storage: Room Temperature Biomineralization of L1 0 CoPt Magnetic Nanoparticles

• Published in: Advanced functional materials 2015-08, Vol.25 (29), p.4590-4600
• Main Authors: Galloway, Johanna M., Talbot, Jennifer E., Critchley, Kevin, Miles, Jim J., Bramble, Jonathan P.
• Format: Article
• Language: English
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.201501090

L1 0 cobalt platinum can be used to record data at approximately sixfold higher densities than it is possible to on existing hard disks. Currently, fabricating L1 0 CoPt requires high temperatures (≈500 °C) and expensive equipment. One ecological alternative is to exploit biomolecules that template nanomaterials at ambient temperatures. Here, it is demonstrated that a dual affinity peptide (DAP) can be used to biotemplate L1 0 CoPt onto a surface at room temperature from an aqueous solution. One part of the peptide nucleates and controls the growth of CoPt nanoparticles from solution, and the other part binds to SiO 2 . A native silicon oxide surface is functionalized with a high loading of the DAP using microcontact printing. The DAP biotemplates a monolayer of uniformly sized and shaped nanoparticles when immobilized on the silicon surface. X‐ray diffraction shows that the biotemplated nanoparticles have the L1 0 CoPt crystal structure, and magnetic measurements reveal stable, multiparticle zones of interaction, similar to those seen in perpendicular recording media. This is the first time that the L1 0 phase of CoPt has been formed without high temperature/vacuum treatment (e.g., annealing or sputtering) and offers a significant advancement toward developing environmentally friendly, biotemplated materials for use in data storage.