Term: spin-state transition
https://doi.org/10.1351/goldbook.S05877

Definition:
An electronic transition from a high-spin state to a low-spin state, or vice versa. Example: With an increase in temperature Co3+ ions in LaCoO3 transform from a low-spin state (t 2g 6 e g 0) to the high-spin state (t 2g 4 e g 2).

Related Terms:
1) high-spin (http://doi.org/10.1351/goldbook.LT06788).
2) low-spin state (http://doi.org/10.1351/goldbook.LT07067).

Source: PAC, 1994, 66, 577. 'Definitions of terms relating to phase transitions of the solid state (IUPAC Recommendations 1994)' on page 591 (https://doi.org/10.1351/pac199466030577)

Citation: 'spin-state transition' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.S05877

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