An electron-ordering transition occurring in a mixed-valent system that results in
an ordering of formal
valence states in the low-temperature phase. Example: The prototype system, first identified
by Verwey, is the ferrospinel magnetite,
Fe3+[Fe3+Fe2+]O4 in which an ordering of
Fe3+
and
Fe2+
ions within octahedral sites is thought to occur
below
.
Source:
PAC, 1994, 66, 577
(Definitions of terms relating to phase transitions of the solid state (IUPAC Recommendations
1994))
on page 593
Cite as:
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.
in flame emission and absorption spectrometry
