Publications by authors named "Miralem Salihovic"

2 Publications

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Confined Etching within 2D and 3D Colloidal Crystals for Tunable Nanostructured Templates: Local Environment Matters.

ACS Appl Mater Interfaces 2017 Feb 17;9(4):3931-3939. Epub 2017 Jan 17.

Department of Chemistry and Physics of Materials, University of Salzburg , Hellbrunner Straße 34/III, A-5020 Salzburg, Austria.

We report the isotropic etching of 2D and 3D polystyrene (PS) nanosphere hcp arrays using a benchtop O radio frequency plasma cleaner. Unexpectedly, this slow isotropic etching allows tuning of both particle diameter and shape. Due to a suppressed etching rate at the point of contact between the PS particles originating from their arrangement in 2D and 3D crystals, the spherical PS templates are converted into polyhedral structures with well-defined hexagonal cross sections in directions parallel and normal to the crystal c-axis. Additionally, we found that particles located at the edge (surface) of the hcp 2D (3D) crystals showed increased etch rates compared to those of the particles within the crystals. This indicates that 2D and 3D order affect how nanostructures chemically interact with their surroundings. This work also shows that the morphology of nanostructures periodically arranged in 2D and 3D supercrystals can be modified via gas-phase etching and programmed by the superlattice symmetry. To show the potential applications of this approach, we demonstrate the lithographic transfer of the PS template hexagonal cross section into Si substrates to generate Si nanowires with well-defined hexagonal cross sections using a combination of nanosphere lithography and metal-assisted chemical etching.
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http://dx.doi.org/10.1021/acsami.6b14226DOI Listing
February 2017

The vibrational and configurational entropy of α-brass.

J Chem Thermodyn 2014 Apr;71(100):126-132

Materialforschung und Physik, Universität Salzburg, Hellbrunnerstr. 34, A-5020 Salzburg, Austria.

The heat capacities of two samples of a fcc Cu-Zn alloy with the composition CuZn15 and CuZn34 were measured from  = 5 K to 573 K using relaxation and differential scanning calorimetry. Below ∼90 K, they are characterised by negative excess heat capacities deviating from ideal mixing by up to -0.20 and -0.44 J · mol · K for CuZn15 and CuZn34, respectively. The excess heat capacities produce excess vibrational entropies, which are less negative compared to the excess entropy available from the literature. Since the literature entropy data contain both, the configurational and the vibrational part of the entropy, the difference is attributed to the excess configurational entropy. The thermodynamics of different short-range ordered samples was also investigated. The extent of the short-range order had no influence on the heat capacity below  = 300 K. Above  = 300 K, where the ordering changed during the measurement, the heat capacity depended strongly on the thermal history of the samples. From these data, the heat and entropy of ordering was calculated. The results on the vibrational entropy of this study were also used to test a relationship for estimating the excess vibrational entropy of mixing.
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http://dx.doi.org/10.1016/j.jct.2013.11.012DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4047615PMC
April 2014