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arXiv · 1611.03281

Enhanced magnetocaloric effect in a proximity of magnetization steps and jumps of spin-1/2 XXZ Heisenberg regular polyhedra

K. Karlova·J. Strecka·J. Richter
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Abstract

The magnetization process and adiabatic demagnetization of the antiferromagnetic spin-1/2 XXZ Heisenberg clusters with the shape of regular polyhedra (tetrahedron, octahedron, cube, icosahedron and dodecahedron) are examined using the exact diagonalization method. It is demonstrated that a quantum (xy) part of the XXZ exchange interaction is a primary cause for presence of additional intermediate magnetization plateaux and steps, which are totally absent in the limiting Ising case. The only exception to this rule is the spin-1/2 XXZ Heisenberg tetrahedron, which shows just a quantitative shift of the level-crossing fields related to two magnetization steps. It is evidenced that the spin-1/2 XXZ Heisenberg regular polyhedra exhibit an enhanced magnetocaloric effect in a proximity of the magnetization steps and jumps, which are accompanied with a rapid drop (rise) of temperature just above (below) of the level-crossing field when the magnetic field is removed adiabatically.

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K. Karlova, J. Strecka, J. Richter. 2016-11-10. Enhanced magnetocaloric effect in a proximity of magnetization steps and jumps of spin-1/2 XXZ Heisenberg regular polyhedra. https://doi.org/10.1088/1361-648x%2Faa53ab

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