Microscopic dynamics of molecular liquids and glasses: Role of orientations and translation-rotation coupling

Details Microscopic dynamics of molecular liquids and glasses: Role of orientations and translation-rotation coupling Microscopic dynamics of molecular liquids and glasses: Role of orientations and translation-rotation coupling

2001-05-21

arxiv.org/abs/cond-mat/0105393v1

Physics

Condensed Matter

Disordered Systems and Neural Networks

26 pages 24 figures

Scientific paper

10.1103/PhysRevE.64.051505

We investigate the dynamics of a fluid of dipolar hard spheres in its liquid and glassy phase, with emphasis on the microscopic time or frequency regime. This system shows rather different glass transition scenarios related to its rich equilibrium behavior which ranges from a simple hard sphere fluid to a long range ferroelectric orientational order. In the liquid phase close to the ideal glass transition line and in the glassy regime a medium range orientational order occurs leading to a softening of an orientational mode. To investigate the role of this mode we use the molecular mode-coupling equations to calculate the spectra $\phi_{lm}^{\prime \prime}(q,\omega)$ and $\chi _{lm}''(q,\omega)$. In the center of mass spectra $ \phi_{00}''(q,\omega)$ and $\chi_{00}''(q,\omega)$ we found besides a high frequency peak at $\omega _{hf}$ a peak at $\omega_{op}$, about one decade below $\omega_{hf}$. $\omega _{op}$ has almost no $q$-dependence and exhibits an ``isotope'' effect $\omega _{op}\propto I^{-1/2}$, with $I$ the moment of inertia. We give evidence that the existence of this peak is related to the occurrence of the medium ranged orientational order. It is shown that some of these feature also exist for schematic mode coupling models.

Affiliated with

Also associated with

No associations

Rating

Microscopic dynamics of molecular liquids and glasses: Role of orientations and translation-rotation coupling does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Microscopic dynamics of molecular liquids and glasses: Role of orientations and translation-rotation coupling, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Microscopic dynamics of molecular liquids and glasses: Role of orientations and translation-rotation coupling will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-564572