A transition observed in certain rare-earth and actinide materials in which the electronic occupation of the 4f or 5f
orbital changes with external conditions for example, temperature and pressure. Example: The transition at approximately
where black, semiconducting
Sm2+S2− changes to golden metallic
(Sm3++e−)S2−.
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.
doi:10.1351/goldbook.
