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nanotimes News in Brief
The development of a new combination of poly- mers associating sugars with oil-based macromole- cules makes it possible to design ultra-thin films capable of self-organization with a 5-nanometer resolution. This opens up new horizons for incre- asing the capacity of hard discs and the speed of microprocessors. The result of a French-American collaboration spearheaded by the Centre de Re- cherches sur les Macromolécules Végétales (CNRS), this work has led to the filing of two patents. It is published in the journal ACS Nano. This new class of thin films based on hybrid copolymers could give rise to numerous applications in flexible electronics, in areas as diverse as nanolithography, biosensors and photovoltaic cells.
Julia D. Cushen, Issei Otsuka, Christopher M. Bates, Sami Halila, Sébastien Fort, Cyrille Rochas, Jeffrey A. Easley, Erica L. Rausch, Anthony Thio, Redouane Borsali, C. Grant Willson, and Christopher J. Ellison: Oligosaccha- ride/Silicon-Containing Block Copolymers with 5nm Features for Lithographic Applications, In: ACS Nano, Volume 6, Issue 4, April 24, 2012, Pages 3424-3433, DOI:10.1021/nn300459r: http://dx.doi.org/10.1021/nn300459r
12-04 :: April/May 2012
this atomic structure. This understanding ultimately could help manufacturers fine-tune such properties of metallic glasses as ductility, the ability to change shape under force without breaking, and formability, the ability to form a glass without crystalizing.
Researchers widely believe that atoms in metallic glasses are arranged only as pentagons in an order known as five-fold rotational symmetry. However, in studies of a zirconium-copper-aluminum metallic glass, Paul Voyles‘ team found there are clusters of squares and hexagons-in addition to clusters of pentagons, some of which form chains-all located within the space of just a few nanometers. “One or two nanometers is a group of about 50 atoms-and it‘s how those 50 atoms are arranged with respect to one another that‘s the new and interesting part,” he says.
For Voyles and his team, the next step will be to calculate the properties of the most realistic structu- ral models of metallic glass they have developed to learn how those properties relate to the structure.
Jinwoo Hwang, Z. H. Melgarejo, Y. E. Kalay, I. Kalay, M. J. Kramer, D. S. Stone, and P. M. Voyles: Nanoscale Struc- ture and Structural Relaxation in Zr50
Cu45
Drawing on powerful computational tools and a state-of-the-art scanning transmission electron microscope, a team of University of Wisconsin- Madison and Iowa State University (US) materials science and engineering researchers has discovered a new nanometer-scale atomic structure in solid metallic materials known as metallic glasses. The findings fill a gap in researchers‘ understanding of
Al5 Bulk Metal-
lic Glass, In: Physical Review Letters, Vol. 108, Issue 19, May 11, 2012, Article 195505 [5 pages], DOI:10.1103/ PhysRevLett.108.195505: http://dx.doi.org/10.1103/PhysRevLett.108.195505