Plihon, N.Corr, C. S.Chabert, P.2015-11-062015-11-060003-6951http://hdl.handle.net/1885/16392Double-layers (DLs) were observed in the expanding region of an inductively coupled plasma with Ar–SF₆ gas mixtures. No DL was observed in pure argon or SF₆ fractions below a few percent. They exist over a wide range of power and pressure although they are only stable for a small window of electronegativity (typically between 8% and 13% of SF₆ at 1 mTorr), becoming unstable at higher electronegativity. They seem to be formed at the boundary between the source tube and the diffusion chamber and act as an internal boundary [the amplitude being roughly 1.5(kTe∕e)] between a high electron density, high electron temperature, low electronegativity plasma upstream (in the source), and a low electron density, low electron temperature, high electronegativity plasma downstream.http://www.sherpa.ac.uk/romeo/issn/0003-6951..."Publishers version/PDF may be used on author's personal website, institutional website or institutional repository" from SHERPA/RoMEO site (as at 6/11/15). Copyright 2005 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Applied Physics Letters and may be found at https://doi.org/10.1063/1.1869533Keywords: Boundary conditions; Carrier concentration; Diffusion; Electric charge; Multilayers; Pressure effects; Thermal effects; Double layer formation; Electronegative plasma; Gas mixtures; Internal boundary; Inductively coupled plasma2005-02-2410.1063/1.18695332015-12-08