The region in which non-specifically adsorbed ions are accumulated and distributed
by the contrasting action of the electric field and thermal motion. Counter and
co-ions in immediate contact with the surface are said to be located in the
Stern layer. Ions farther away from the surface form the diffuse layer or Gouy layer.
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