No data available.

Please log in to see this content.

You have no subscription access to this content.

No metrics data to plot.

The attempt to load metrics for this article has failed.

The attempt to plot a graph for these metrics has failed.

Relationship between neighbor number and vibrational spectra in disordered colloidal clusters with attractive interactions

Rent:

Rent this article for

USD

10.1063/1.4774076

### Abstract

We study connections between vibrational spectra and average nearest neighbor number in disordered clusters of colloidal particles with attractive interactions. Measurements of displacement covariances between particles in each cluster permit calculation of the stiffness matrix, which contains effective spring constants linking pairs of particles. From the cluster stiffness matrix, we derive vibrational properties of corresponding “shadow” glassy clusters, with the same geometric configuration and interactions as the “source” cluster but without damping. Here, we investigate the stiffness matrix to elucidate the origin of the correlations between the median frequency of cluster vibrational modes and average number of nearest neighbors in the cluster. We find that the mean confining stiffness of particles in a cluster, i.e., the ensemble-averaged sum of nearest neighbor spring constants, correlates strongly with average nearest neighbor number, and even more strongly with median frequency. Further, we find that the average oscillation frequency of an individual particle is set by the total stiffness of its nearest neighbor bonds; this average frequency increases as the square root of the nearest neighbor bond stiffness, in a manner similar to the simple harmonic oscillator.

© 2013 American Institute of Physics

Received 17 October 2012
Accepted 18 December 2012
Published online 11 January 2013

Acknowledgments: We thank Kevin Aptowicz, Piotr Habdas, Carl Goodrich, and Andrea Liu for helpful discussions, and we gratefully acknowledge financial support from the National Science Foundation through Grant Nos. DMR12-05463, the PENN MRSEC DMR11-20901, and NASA NNX08AO0G. Z.Z. gratefully acknowledges financial support from the National Basic Research Program of China through Grant No. 2012CB821500.

Article outline:

I. INTRODUCTION

II. BACKGROUND

A. Experimental system

B. Theoretical analysis

C. Finite-sampling correction

III. RESULTS

A. Effect of on ω_{ Med }

B. Vibrational properties of individual particles

IV. DISCUSSION AND SUMMARY

/content/aip/journal/jcp/138/12/10.1063/1.4774076

http://aip.metastore.ingenta.com/content/aip/journal/jcp/138/12/10.1063/1.4774076

Article metrics loading...

/content/aip/journal/jcp/138/12/10.1063/1.4774076

2013-01-11

2014-04-20

Full text loading...

### Most read this month

Article

content/aip/journal/jcp

Journal

5

3

Commenting has been disabled for this content