Quasi-two-dimensional complex plasma containing spherical particles and their binary agglomerates

TL;DR

This study reports a novel quasi-two-dimensional complex plasma system with monodisperse microspheres and their dimers, revealing nonmonotonic separation behavior and a disordered solid state.

Contribution

It introduces a new plasma system with binary agglomerates and characterizes their structural and dynamic properties, including identification methods and pressure-dependent behaviors.

Findings

Particles and dimers form two sublayers at different heights.

The system remains disordered without crystallization.

Particle separations vary nonmonotonically with pressure.

Abstract

A new type of quasi-two-dimensional complex plasma system was observed which consisted of monodisperse microspheres and their binary agglomerations (dimers). The particles and their dimers levitated in a plasma sheath at slightly different heights and formed two distinct sublayers. The sys- tem did not crystallize and may be characterized as disordered solid. The dimers were identified based on their characteristic appearance in defocused images, i.e., rotating interference fringe pat- terns. The in-plane and inter-plane particle separations exhibit nonmonotonic dependence on the discharge pressure which agrees well with theoretical predictions.