A quantity which approximates to the characteristic length
associated with certain number density
profiles of diffuse layers.
is defined as the separation between two interacting entities (molecules, macromolecular
segments, ions, spins), either in bulk or interfacial regions, beyond which an appropriate
function, referred to as pair correlation function, either decays (e.g. to
of an 'initial
' value) or vanishes.
A characteristic length must be confused neither with the effective thickness of the
, nor with the range (effective distance) of the intermolecular
(pair) potential. This range is defined by the distance over which this potential
and the corresponding correlation function both vanish.
PAC, 1994, 66, 1667
(Thin films including layers: terminology in relation to their preparation and characterization
(IUPAC Recommendations 1994))
on page 1674
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by
A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997).
XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic,
J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8. https://doi.org/10.1351/goldbook