Frustration effects in magnetic molecules

Abstract

Besides being a fascinating class of new materials, magnetic molecules provide the opportunity to study concepts of condensed matter physics in zero dimensions. This contribution will exemplify the impact of molecular magnetism on concepts of frustrated spin systems. We will discuss spin rings and the unexpected rules that govern their low-energy behavior. Rotational bands, which are experimentally observed in various molecular magnets, provide a useful, simplified framework for characterizing the energy spectrum, but there are also deviations thereof with far-reaching consequences. It will be shown that localized independent magnons on certain frustrated spin systems lead to giant magnetization jumps, a new macroscopic quantum effect. In addition a frustration-induced metamagnetic phase transitions will be discussed, which demonstrates that hysteresis can exist without anisotropy. Finally, it is demonstrated that frustrated magnetic molecules could give rise to an enhanced magnetocaloric effect.

6 pages, 4 figures; submitted to J. Low. Temp. Phys.; proceedings of the Sixth International Symposium on Crystalline Organic Metals, Superconductors, and Ferromagnets (ISCOM)

References in corpus (8)

• Macroscopic magnetization jumps due to independent magnons in frustrated quantum spin lattices
• Magnetocaloric effect in one-dimensional antiferromagnets
• Exact eigenstates and macroscopic magnetization jumps in strongly frustrated spin lattices
• Independent magnon states on magnetic polytopes
• Finite low-temperature entropy of some strongly frustrated quantum spin lattices in the vicinity of the saturation field
• Elementary excitations in the cyclic molecular nanomagnet Cr8
• Metamagnetic phase transition of the antiferromagnetic Heisenberg icosahedron
• Quantum numbers for relative ground states of antiferromagnetic Heisenberg spin rings

Cited by in corpus (3)

• Enhanced magnetocaloric effect in a proximity of magnetization steps and jumps of spin-1/2 XXZ Heisenberg regular polyhedra
• Large-scale numerical investigations of the antiferromagnetic Heisenberg icosidodecahedron
• Reminiscence of a magnetization plateau in a magnetization processes of toy-model triangular and tetrahedral clusters