Low temperature structural transitions in dipolar hard spheres
- Author(s)
- A. O. Ivanov, S. S. Kantorovich, L. Rovigatti, J. M. Tavares, F. Sciortino
- Abstract
We investigate the structural chain-to-ring transition at low temperature in a gas of dipolar hard spheres (DHS). Due to the weakening of entropic contribution, ring formation becomes noticeable when the effective dipole-dipole magnetic interaction increases. It results in the redistribution of particles from usually observed flexible chains into flexible rings. The concentration (ρ) of DHS plays a crucial part in this transition: at a very low ρ only chains and rings are observed, whereas even a slight increase of the volume fraction leads to the formation of branched or defect structures. As a result, the fraction of DHS aggregated in defect-free rings turns out to be a non-monotonic function of ρ. The average ring size is found to be a slower increasing function of ρ when compared to that of chains. Both theory and computer simulations confirm the dramatic influence of the ring formation on the ρ-dependence of the initial magnetic susceptibility (χ) when the temperature decreases. The rings due to their zero total dipole moment are irresponsive to a weak magnetic field and drive to the strong decrease of the initial magnetic susceptibility.
- Organisation(s)
- Computational and Soft Matter Physics
- External organisation(s)
- Ural Federal University, Instituto Politécnico de Lisboa, Sapienza University of Rome
- Journal
- Journal of Magnetism and Magnetic Materials
- Volume
- 383
- Pages
- 272-276
- No. of pages
- 5
- ISSN
- 0304-8853
- DOI
- https://doi.org/10.1016/j.jmmm.2014.10.013
- Publication date
- 06-2015
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103023 Polymer physics, 103017 Magnetism, 103029 Statistical physics
- Keywords
- ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials, Condensed Matter Physics
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/83a956fe-74a3-4442-8310-e7d526f2a25e