SURFACE MAGNETISM OF NEARLY MAGNETIC SYSTEMS AND RELATED PROPERTIES

After preliminaries about electron properties, and definitions in magnetism, one treats the magnetism of mononuclear complexes, in particular spin cross-over, showing the role of cooperativity and the sensitivity to external perturbations. Orbital interactions and exchange interaction are explained in binuclear model systems, using orbital overlap and orthogonality concepts to explain antiferromagnetic or ferromagnetic coupling. The phenomenologically useful Spin Hamiltonian is defined. The concepts are then applied to extended molecular magnetic systems, leading to molecular magnetic materials of various dimensionalities exhibiting bulk ferro- or ferrimagnetism. An illustration is provided by Prussian Blue analogues. Magnetic anisotropy is introduced. It is shown that in some cases, a slow relaxation of magnetization arises and gives rise to appealing single-ion magnets, single-molecule magnets or single-chain magnets, a route to store information at the molecular level.

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Description and symmetry of aperiodic crystals

10.1093/oso/9780198824442.003.0002 ◽

2018 ◽

Author(s):

Ted Janssen ◽

Gervais Chapuis ◽

Marc de Boissieu

Keyword(s):

Time Reversal ◽

Mathematical Concept ◽

New Materials ◽

Magnetic Systems ◽

Atomic Structures ◽

Modulated Phases ◽

Quasiperiodic Functions ◽

Aperiodic Crystals ◽

Superspace Description

This chapter first introduces the mathematical concept of aperiodic and quasiperiodic functions, which will form the theoretical basis of the superspace description of the new recently discovered forms of matter. They are divided in three groups, namely modulated phases, composites, and quasicrystals. It is shown how the atomic structures and their symmetry can be characterized and described by the new concept. The classification of superspace groups is introduced along with some examples. For quasicrystals, the notion of approximants is also introduced for a better understanding of their structures. Finally, alternatives for the descriptions of the new materials are presented along with scaling symmetries. Magnetic systems and time-reversal symmetry are also introduced.

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Elastic behavior of magnetic systems with a narrow twofold-degenerate band

Physical Review B ◽

10.1103/physrevb.36.3868 ◽

1987 ◽

Vol 36 (7) ◽

pp. 3868-3873 ◽

Cited By ~ 11

Author(s):

D. K. Ray ◽

S. K. Ghatak

Keyword(s):

Elastic Behavior ◽

Magnetic Systems

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Anomalous spin Hall and inverse spin Hall effects in magnetic systems

Communications Physics ◽

10.1038/s42005-021-00557-9 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

X. R. Wang

Keyword(s):

Hall Effect ◽

Order Parameter ◽

Spin Current ◽

Spin Hall Effect ◽

Magnetic Systems ◽

Charge Current ◽

Spin Currents ◽

Tensor Quantity ◽

Hall Effects ◽

Spin Hall Effects

AbstractSpin current is a very important tensor quantity in spintronics. However, the well-known spin-Hall effect (SHE) can only generate a few of its components whose propagating and polarization directions are perpendicular with each other and to an applied charge current. It is highly desirable in applications to generate spin currents whose polarization can be in any possible direction. Here anomalous SHE and inverse spin-Hall effect (ISHE) in magnetic systems are predicted. Spin currents, whose polarisation and propagation are collinear or orthogonal with each other and along or perpendicular to the charge current, can be generated, depending on whether the applied charge current is along or perpendicular to the order parameter. In anomalous ISHEs, charge currents proportional to the order parameter can be along or perpendicular to the propagating or polarization directions of the spin current.

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