Volume 27, Issue 24 p. 7022-7042

Half-Integer Spin Triangles: Old Dogs, New Tricks

Dr. Athanassios K. Boudalis

Corresponding Author

Dr. Athanassios K. Boudalis

Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), UMR 7504, Université de Strasbourg, CNRS, 67000 Strasbourg, France

Institut de Chimie de Strasbourg (UMR 7177, CNRS-Unistra), Université de Strasbourg, 4 rue Blaise Pascal, CS 90032, 67081 Strasbourg, France

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First published: 18 December 2020
Citations: 10

Graphical Abstract

Triangular tricks: In architecture, relief triangles relieve the stress of the superstructure by distributing it away from the weak points of the underlying wall. In magnetism, spin triangles relieve the stress of competing interactions by distributing local magnetizations to minimize energy. Architectural examples, like the “Lion gate” in Mycenae, are extremely ancient, but spin triangles are slowly catching up.


Spin triangles, that is, triangular complexes of half-integer spins, are the oldest molecular nanomagnets (MNMs). Their magnetic properties have been studied long before molecular magnetism was delineated as a research field. This Review presents the history of their study, with references to the parallel development of new experimental investigations and new theoretical ideas used for their interpretation. It then presents an indicative list of spin-triangle families to illustrate their chemical diversity. Finally, it makes reference to recent developments in terms of theoretical ideas and new phenomena, as well as to the relevance of spin triangles to spintronic devices and new physics.

Conflict of interest

The author declares no conflict of interest.