Counter and co-ions in immediate contact with a surface are said to be located in the Stern layer, and form with the fixed charge a molecular capacitor.
Source:
PAC, 1972, 31, 577
(Manual of Symbols and Terminology for Physicochemical Quantities and Units, Appendix II: Definitions, Terminology and Symbols in Colloid and Surface Chemistry)
on page 618
Transformed and rewritten from PDF version (entry
http://www.iupac.org/goldbook/S06003.pdf)
by: Miloslav Nic, Jiri Jirat, Bedrich Kosata, ICT Prague, Czech Republic
