Hostname: page-component-78c5997874-t5tsf Total loading time: 0 Render date: 2024-11-05T14:34:40.824Z Has data issue: false hasContentIssue false

Development of Block Co-Polymers as Self-Assembling Templates for Magnetic Media and Spin-Valves

Published online by Cambridge University Press:  01 February 2011

Vishal Vitthal Warke
Affiliation:
[email protected], University of Alabama, Department of Chemistry and MINT Center, Tuscaloosa, AL, 35487, United States
Chris Redden
Affiliation:
[email protected], University of Alabama, Department of Chemistry and MINT Center, Tuscaloosa, AL, 35487, United States
Martin Bakker
Affiliation:
[email protected], University of Alabama, Department of Chemistry and MINT Center, Tuscaloosa, AL, 35487, United States
David Nikles
Affiliation:
[email protected], University of Alabama, Department of Chemistry and MINT Center, Tuscaloosa, AL, 35487, United States
Kunlun Hong
Affiliation:
[email protected], Oak Ridge National Laboratory, Center for Nanophase Materials Science, Oak Ridge, TN, 37831, United States
Jimmy Mays
Affiliation:
[email protected], Oak Ridge National Laboratory, Center for Nanophase Materials Science, Oak Ridge, TN, 37831, United States
Phil Britt
Affiliation:
[email protected], Oak Ridge National Laboratory, Center for Nanophase Materials Science, Oak Ridge, TN, 37831, United States
Get access

Abstract

Poly(styrene)-Poly(methylmethacrylate) block co-polymers (PS-b-PMMA) of appropriate block length and PS to PMMA ratio self-assemble into a 2-D hexagonal phase in which the PS majority phase is continuous and surrounds cylinders of the minority, PMMA phase. By UV irradiation and washing with acetic acid it is possible to remove the minority phase to leave empty channels. It is also possible to rearrange the PMMA phase with acetic acid to leave somewhat smaller pores. For most substrates the interactions between the polymer and the substrate surface are such that one block is preferentially adsorbed to the substrate resulting in alignment of the PMMA domains parallel to the substrate surface. It is possible to orient the polymer perpendicular to the surface by first adding a thin film of a random PS-PMMA co-polymer before applying the PS-b-PMMA block co-polymer. However thin films of the random PS-PMMA do not give good surface coatings, and thicker films are generally too thick for the pores in the PS-b-PMMA block co-polymer to be propagated to the substrate surface. For a few substrates, thin PS-b-PMMA films naturally adopt a perpendicular orientation after annealing, washing with acetic acid produces arrays of pores of diameter as small as 3 nm. For a number of other substrates the interaction between the polymer blocks and the surface is such that upon annealing the polymer rearranges to form micron sized domains which are not polymer coated, surrounded a areas which have a thicker polymer coating. We have observed this behavior with both carbon coated substrates and with ITO glass substrates. In both cases the areas of polymer are perpendicularly oriented, and upon washing with acetic acid give rise to pores that extend completely through the polymer film. In some cases films on ITO glass are continuous even after annealing. After washing with acetic acid it was possible to electrodeposit nickel into the pores to give nickel nano-pillars of 18 nm diameter.

Type
Research Article
Copyright
Copyright © Materials Research Society 2006

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1 Bates, F. S., Fredrickson, G. H., Annu. Rev. Phys. Chem. 1990, 41, 525.Google Scholar
2 Thurn-Albrecht, T., Schotter, J., Kastle, A., Emley, N., Shilbauchi, T., Krusin-Elbaum, L., Guarini, K., Black, C. T., Tuominen, M. T., Russell, T. P., Science 2000, 79, 409.Google Scholar
3 Hamley, I. W., The Physics of Block Copolymers; Oxford University Press: Oxford, 1998.Google Scholar
4 Kim, S. O., Solak, H. H., Stoykovich, M. P., Ferrier, N. J., Pablo, J. J. de, Nealey, P. F., Nature 2003, 424, 411.Google Scholar
5 Cheng, J. Y., Ross, C. A., Vanessa, Z. H. C., Thomas, E. L., Rob, G. H. L., Vansco, J. G. Adv. Mater. 2001, 13, No. 15, 1174.Google Scholar
6 Hamley, I. W., Nanotech. 2003, 14, R39–R54.Google Scholar
7 Böker, A., Ph.D. thesis, The University of Bayreuth, Bayreuth, Germany, 2002.Google Scholar
8 Chao, C. Y., Li, X., Ober, C. K., Osuji, C., Thomas, E. L., Adv, E. L.. Funct. Mater. 2004, 14, No.4, 364.Google Scholar
9 Amundson, K., Helfand, E., Quan, X., Smith, S. D., Macromolecules, 1993, 26, 2698.Google Scholar
10 Mansky, P., Liu, Y., Huang, E., Russell, T. P., Hawker, C., Science, 1997, 275, 1458.Google Scholar
11 Peng, J., Xuan, Y., Wang, H., Yang, Y., Li, B., Han, Y. J., Chem. Phys. 2004, 120, No. 23, 11163.Google Scholar
12 Bates, F. S, Fredrickson, G. H., Phys. Today, 1999, 52, 32.Google Scholar
13 Jeong, U., Yeol, D., Kim, J. K., Kim, D. H., Russell, T. P., Hawker, C. J., Adv. Mater. 2003, 15, No. 15, 1247 (and references therein).Google Scholar
14 Hadjichristidis, N., Iatrou, H., Pispas, S., Pitsikalis, M. J., Polym. Sci., Part A: Polym. Chem., 2000, 38, 3211.Google Scholar
15 Hadjichristidis, N., Pispas, S., Floudas, G., Block Copolymers: Synthetic Strategies, Physical Properties, and Applications; John Wiley & Sons, Inc. (US), Hoboken, NJ, 2003.Google Scholar
16 Kellogg, G. J., Walton, D. G., Mayes, A. M., Lambooy, P., Russell, T. P., Gallagher, P. D. Satija, S. K., Phys. Rev. Lett. 1996, 76, 2503.Google Scholar
17 Kim, H. C., Jia, X., Stafford, C. M., Kim, D. H., McCarthy, T. J., Tuominen, C. J., Russell, T. P., Avd. Mater. 2001, 13 No. 11, 795.Google Scholar
18 Xu, T., Stevens, J., Villa, J., Goldbatch, J. T., Guarini, K. W., Black, C. T., Hawker, C. J., Russell, T. P., Adv. Funct. Mater. 2003, 13, No. 9, 698.Google Scholar
19 Thurn-Albrecht, T., Derouchey, J., Russell, T. P., T. P. Macromolecules 2000, 33, 3250.Google Scholar
20 Sivaniah, E., Hayashi, Y., Iino, M., Hashimoto, T., Fukunaga, K., Macromolecules, 2003, 36, 5894.Google Scholar
21 Sivaniah, E., Hayashi, Y., Matsubara, S., Kiyono, S., Hashimoto, T., Fukunaga, K., Kramer, E. J., Mates, T., Macromolecules, 2005, 38, 1837.Google Scholar